
If you are using Selenium, then you probably need the minimized version of the operating systems that are customized for a particular task – to work with browsers. Today we will talk about how we created this minimized Windows 7 image for Nerrvana, which installs on 7GB partition and works in 512MB of RAM.
All the troubles and ordeals of the process are explicitly omitted. Only their description could devote an entire post, and who will be interested in them other than the author anyway?
To customize Windows 7, I used R7 Lite. Thanks for the tip from customization gurus, as all my attempts to use vLite (for Windows XP, we used xLite) did not lead to anything good.
To start you need the original Windows 7 Home Premium image. So here are the instructions to minimize this particular version.
Why Premium? If you are using VMWare or KVM virtualization it is quite possible that Windows Home Basic will work for you. We are using Xen on 64 bit CentOS and through lots of experimentation and time I found one inexplicable phenomenon – even with the original Home Basic (it exists only in the 32 bit version) I did not manage to install Adobe Flash on IE; install just mysteriously fails. Then I took the less appealing route for us, because it has more features that we just do not need; Home Premium 64 bit, put it ‘as is’ on Xen, and Flash installed without a problem. However Flash installed just fine on Home Basic on VMWare, running on a 64 bit computer. Who knew!
From this story the practical advice follows – install the original image to the virtualization platform of your choice, and check all the details before you start minimization. In this case you will know that failure was caused by your customization process (after all, you have verified it with original image install and it all worked). It just might save you a lot of time and nerves.
Launch RT7 Lite, select Windows 7 image and specify the folder to unpack it to.

During the extraction process you will see a pop-up – select the version of Win 7 you will be working with. Why it pops up – I have no idea, as it should know what ISO we use from the ISO itself?

After loading the image you can choose and use a previously created configuration file. When you will generate the customized install image, you can, again, save changes on this page to a new file to use it in the next iteration, if it is required. Just do it before saving the customized image to an ISO file in the end.
During my work I accumulated a dozen of them. Here is my latest configuration file:
[OS Name= Windows 7 HOMEPREMIUM] [Date= 6/23/2012 8:03:53 PM] [Microsoft .NET FrameWork= 3.5] [Version: Release Candidate 1.7.0] Blackviper=Default [Update] [Driver] [Language] [Application] [Components] Ease of Access Center=True Action Center=True Calculator=True Character Map=True Clear Type Tuner=True Default Computer Program Access=True Diagnostics Troubleshooting Wizard=True Disk CleanUp=True InboxGames=True Chess=True FreeCell=True Hearts=True Shanghai=True Minesweeper=True More Games=True Internet Games=True Internet Backgammon=True Internet Checkers=True Internet Spades=True PurblePlace=True Solitaire=True SpiderSolitaire=True Infrared File Transfer Application=True Mobility Center=True Notepad=True On-Screen Magnifier=True Paint=True People Near Me=True Projector Connectivity=True Speech Recognition=True Sticky Notes=True Welcome Center=True Windows Contacts=True FaxServicesClientPackage=True Windows Repair Disc=True WindowsGadgetPlatform=True WindowsSideShow=True Wordpad=True Write=True 1394 Driver=True D_ATI Technologies=True D_Intel Corporation=True D_NVIDIA=True Media Managers=True Audio=True High Definition Audio Driver (Default)=True Creative Technology=True Microsoft Audio Home Theatre Effects=True WDM Audio Drivers=True 1394 Desktop Camera=True M_AFA Technologies=True M_ATI Technologies=True M_Aver Media Technologies=True M_Conexant=True M_Hauppauge=True IEEE 1394 DV Camera=True M_IEEE 1394 Tape Subunit Devices=True M_Luminate-Angel Devices=True M_Microsoft Media Manager=True M_ViXS=True M_Windows SideShow Driver=True Modem=True MO_Agere Systems=True MO_AIWA=True MO_Anchor Datacom BV=True MO_Archtek Telecom=True MO_ARN=True MO_Askey and Cardinal=True MO_ATI Technologies=True MO_Banksia,Meastro=True MO_Boca Research=True MO_Brother=True MO_BSB Datentechnik=True MO_Compaq=True MO_Conexant=True MO_Creative Labs=True MO_Creatix Polymedia=True MO_CPV-Stollmann Datensysteme=True MO_Digicom=True MO_Dynalinks and Todos=True MO_Eiger Labs=True MO_E-Tech=True MO_ELSA=True MO_Fujtisu=True MO_Gateway 2000=True MO_GSM Cellular=True MO_Haeussler DK & NO=True MO_Hayes Accura=True MO_Hayes=True MO_Hot Line Export AB=True MO_I-O DATA DEVICE=True MO_Infotel=True MO_Intertex=True MO_Ke Kommunikations Elektronic=True MO_KORTEX=True MO_LASAT COMMUNICATIONS=True MO_Lucent=True MO_Megasoft=True MO_Megahertz Corporation=True MO_Metricom=True MO_Microcom=True MO_MICRO Research=True MO_Motorola=True MO_Modular Technology=True MO_Multitech Systems=True MO_NEC=True MO_Neuhaus Telekommunikation=True MO_NISSEI=True MO_Nokia=True MO_Novalink Technologies=True MO_NTT Docomo=True MO_OLITEC=True MO_OMRON=True MO_OPTION International=True MO_Ositech Communications=True MO_Pace=True MO_Panasonic=True MO_Penril Datability Networks=True MO_Practical Peripherals=True MO_Psion Dacom=True MO_Racal-Airtech=True MO_Rockwell & Cirrus=True MO_Sierra Semiconductor=True MO_SONY=True MO_Sony Ericsson=True MO_Sony Ericsson and Motorola-Bluetooth Modem=True MO_Standard Modem Drivers=True MO_Suntac=True MO_Supra Corporation=True MO_TDK Corporation=True MO_TOSHIBA=True MO_Texas Instrument=True MO_TKR=True MO_TRON B.V. Datacommunicatie=True MO_U.S. Robotics-France=True MO_U.S. Robotics-Europe=True MO_U.S. Robotics-Sportster=True MO_U.S. Robotics,Telepath,IBM=True MO_V.DOT=True MO_Xircom=True MO_Zoom Telephonics=True MO_Zypcom=True MO_ZYXEL=True Printers=True P_Brother=True P_Canon=True P_Epson=True P_Fuji Xerox=True P_Gestetner=True P_Hewlett-Packard=True P_Infotec=True P_KONICA MINOLTA=True P_Kyocera=True P_Lanier=True P_Lexmark International=True P_Microsoft=True P_Okidata=True P_Ricoh=True P_Samsung=True P_Savin=True P_Sharp=True P_Sony=True P_TOSHIBA=True P_Xerox=True P_XPS Document Writer=True Scanners=True S_Brother=True S_Canon=True S_Epson=True S_Hewlett-Packard=True S_Kyocera Mita=True S_Lexmark=True S_Microsoft=True S_Ricoh=True S_Samsung=True S_Xerox Corporation=True TV Tuners=True TV_ADS Technologies=True TV_ASUSTEK Computer=True TV_Aver Media Technologies=True TV_Bitland=True TV_Creatix=True TV_Compro Technology=True TV_Hauppauge=True TV_KNC ONE GMBH=True TV_KWorld=True TV_NXP Semiconductors=True TV_Philips Semi-Conductors=True TV_Pinnacle Systems=True TV_Terratec Electronic GmbH=True TV_VidZ Media=True D_Bluetooth=True Digital Media Devices=True Diva Client=True D_Fax=True Floppy Drive=True Smart Card Drivers=True USB=True Language Packs=True ar-SA=True bg-BG=True zh-CN=True zh-TW=True zh-HK=True hr-HR=True cs-CZ=True da-DK=True nl-NL=True et-EE=True fi-FI=True fr-FR=True de-DE=True el-GR=True he-IL=True hu-HU=True it-IT=True ja-JP=True ko-KR=True lt-LT=True lv-LV=True nb-NO=True pl-PL=True es-ES=True pt-BR=True pt-PT=True ro-RO=True ru-RU=True sr-Latn-CS=True sk-SK=True sl-SI=True sv-SE=True th-TH=True tr-TR=True uk-UA=True Autoplay=True Sample Music and Videos=True Sample Pictures=True Screensavers=True Sound Recorder=True Windows Codec Packages=True OpticalMediaDisc=True Windows ISO Burn=True MediaCenter=True Windows Media Encoders and Decoders=True WindowsMediaPlayer=True Windows Photo Gallery (shimgvw)=True Windows Photo Viewer=True Windows Picture Acquisition Wizard=True Windows Sounds=True Windows wallpapers=True IIS-WebServerRole=True Network Explorer=True Windows Remote Assistance=True Remote Desktop Connection=True TCP/IP Applications=True TelnetClient=True TelnetServer=True Windows Mail=True Windows Presentation Foundation Host=True AxInstSV=True SensrSvc=True AeLookupSvc=True ALG=True BFE=True BDESVC=True wbengine=True bthserv=True CertPropSvc=True KeyIso=True Browser=True VaultSvc=True UxSms=True DPS=True WdiServiceHost=True WdiSystemHost=True defragsvc=True TrkWks=True MSDTC=True EFS=True EapHost=True Fax=True fdPHost=True FDResPub=True hkmsvc=True HomeGroupListener=True HomeGroupProvider=True hidserv=True IKEEXT=True UI0Detect=True SharedAccess=True iphlpsvc=True PolicyAgent=True KtmRm=True lltdsvc=True Mcx2Svc=True clr_optimization_v2.0.50727_64=True clr_optimization_v2.0.50727_32=True MSiSCSI=True swprv=True MMCSS=True NetTcpPortSharing=True Netlogon=True napagent=True NlaSvc=True WPCSvc=True PNRPsvc=True p2psvc=True p2pimsvc=True pla=True IPBusEnum=True PNRPAutoReg=True WPDBusEnum=True Power=True Spooler=True wercplsupport=True PcaSvc=True ProtectedStorage=True QWAVE=True RasAuto=True RasMan=True SessionEnv=True TermService=True RpcLocator=True RemoteRegistry=True RemoteAccess=True seclogon=True SstpSvc=True wscsvc=True LanmanServer=True ShellHWDetection=True SCardSvr=True SCPolicySvc=True SNMPTRAP=True sppuinotify=True SSDPSRV=True SysMain=True SENS=True TabletInputService=True lmhosts=True THREADORDER=True TBS=True upnphost=True vds=True VSS=True WebClient=True AudioSrv=True AudioEndpointBuilder=True SDRSVC=True WbioSrvc=True idsvc=True WcsPlugInService=True wcncsvc=True WinDefend=True wudfsvc=True WerSvc=True Wecsvc=True MpsSvc=True stisvc=True ehRecvr=True ehSched=True WMPNetworkSvc=True TapiSrv=True FontCache3.0.0.0=True WinRM=True SearchEngine-Client-Package=True WinHttpAutoProxySvc=True dot3svc=True Wlansvc=True wmiApSrv=True LanmanWorkstation=True WwanSvc=True Adapter Troubleshooter=True Advanced UAC=True Auto File System Converter=True Auto File System Format Utility=True Corrupted File Recovery=True Device Pairing Application=True Display Color Calibration=True DPI Scaling=True Eventing Command Line Utility=True Location and Mobile PC Sensor=True Manual windows setup=True Microsoft Custom Dictionary=True Microsoft Sync Center=True Natural Language=True Narrator=True On-Screen Keyboard=True Recovery=True TabletPCOC=True Thumbnail Cache=True Windows Anytime Upgrade=True Windows Cabinet Maker=True Windows Easy Transfer=True Windows Font Viewer=True Windows Help=True Windows Memory Diagnostic=True Windows Portable Device=True Windows PowerShell=True Workspace Runtime=True Xps-Foundation-Xps-Viewer=True Zip Folder=True [Features] MediaPlayback=False OpticalMediaDisc=False MediaCenter=False WindowsMediaPlayer=False NetFx3=False Printing-Foundation-Features=False Printing-Foundation-InternetPrinting-Client=False FaxServicesClientPackage=False [Control Panel Remove] [Control Panel Add] Control panel view=Category [Desktop] [Desktop Taskbar] [Explorer Shortcuts] [Explorer Context] [Explorer Views] [Security] Anti spyware=Default UAC=Default Windows Firewall=Default [Services] Background Intelligent Transfer Service=Manual Network Connections=Disable Network List Service=Disable Windows Modules Installer=Manual Windows Update=Manual [System] Windows Update=Disable [Visual Effects] [Internet Explorer] Warn On Intranet=Disable Welcome Page=Disable Play Background Sound=Disable Default Search Page=www.google.com Script Debugger=Disable Show URL ToolBar=Enable Show full URL=Enable Save Session History and Exit=Disable No Update Checking=Enable IE Phishing Filter=Disable Block popups=Disable Show URL in statusbar=Disable Show Status Bar=Disable Proxy=Disable Default Start Page=Custom... [Media Center] CustomReg= CustomBat= [Un-Attended] productkey=RHPQ2$RMFJH$74XYM$BH4JX$XM76F Skip Auto Activation=True Accept EULA=True Select this version on install=True Setup Language=en-US Fullname=Nerrvana Computername=win7template organization=Deep Shift Labs Logon count=1 Network location=Home Protect your computer=Do not Install Selective Updates Specify=True Keyboard=United States Currency and date format=English (United States) UI Language=en-US Timezone=(UTC) Coordinated Universal Time [Screen Saver] [Themes] [WallPaper] [Gadgets] [Documents] [Sample Musics] [Sound] Windows Ding=Default= Windows Logoff Sound=Default= Windows Exclamation=Default= Windows Hardware Fail=Default= Windows Notify=Default= Windows Restore=Default= Windows Recycle=Default= Windows Battery Critical=Default= Windows Balloon=Default= Windows Minimize=Default= Windows Startup=Default= Windows Hardware Remove=Default= Windows Critical Stop=Default= Windows Default=Default= Windows Feed Discovered=Default= Windows Logon Sound=Default= Windows Error=Default= Windows Information Bar=Default= Windows Hardware Insert=Default= Windows Battery Low=Default= Windows Shutdown=Default= AppInstallationMode=0 DriverForceIntegration=False |
Next, go to the tab ‘Task’ and select all of the check boxes. Here you actually tell RT7 Lite what features of it you will be using. To start, you can mark them all to have a look and then just use what you need. Today we’ll go over the features (vertical tabs on left side of RT7 Lite UI).

On the ‘Customization’ tab you can add some files to the image files that you need after installation – browsers installs, Selenium, your own scripts. You can copy files to an installed Windows too, using VNC Viewer or TeamViewer.

Tab ‘Integration’ allows you to immediately install the necessary software updates, language packs, applications and drivers. I did not use it. This could be handy if you use Rt7 Lite to customize for big deployments – install 100 office PC’s with all standard software installed, for example.

On the ‘Un-Attended’ tab you can answer all the questions that Windows asks during installation. Before I started using Rt7 Lite I tried using Win Toolkit where I learned the following information:
In order to not display the serial page during install you need to enter a default serial key. These are:
Windows 7:
Ultimate – D4F6K-QK3RD-TMVMJ-BBMRX-3MBMV
Professional – HYF8J-CVRMY-CM74G-RPHKF-PW487
Home Premium – RHPQ2-RMFJH-74XYM-BH4JX-XM76F
Home Basic – YGFVB-QTFXQ-3H233-PTWTJ-YRYRV
Starter – 7Q28W-FT9PC-CMMYT-WHMY2-89M6GWindows Vista:
Ultimate – VMCB9-FDRV6-6CDQM-RV23K-RP8F7
Business – 4D2XH-PRBMM-8Q22B-K8BM3-MRW4W
Home Premium – X9HTF-MKJQQ-XK376-TJ7T4-76PKF
Home Basic – RCG7P-TX42D-HM8FM-TCFCW-3V4VD
Starter – X9PYV-YBQRV-9BXWV-TQDMK-QDWK4NOTE: These keys are provided by Microsoft, they are only used to make the installation unattended as they keep the 30 day trial after installation.
… and use this license. After completion I passed Xen image to Dima who will finally replace this license with a real one and activate it.

It is important to visit the tab ‘Tweaks’ before ‘Features Removal’. I did not know this and spent a lot of time determining the services that can be disabled completely or disabled during normal Windows usage – Selenium testing. If you go to the ‘Services’ sub-tab (horizontal tab line in main RT7 Lite frame) on ‘Tweaks’, then at the bottom you will see a drop-down list where you can choose Black Viper’s presets.

On this page in the left column, you can click on the Windows service description and view more details about the service and its dependencies. Profiles (most right columns) on this site are exactly the same as used by RT7 Lite. For example, selecting in RT7 Lite Black Viper’s preset ‘bare-bones’ you will get a corresponding list of services. Now you need to take a screenshot of this list, as we can remove most of the disabled services from our Windows image, when we go to the ‘Features Removal’ tab. You will need some program which can take screenshots and scroll at the same time, like FastStone Capture.
However, you do not need to remove Windows services, but just use the ‘bare-bones’ profile and leave services in the operating system in status Disabled. Installation will require more disk space, but who is very concerned about this these days? Especially if you create machines using virtual snapshot technology, when copying of the entire image is not required, and a new machine is available within seconds after receiving the command to create it. The only thing – when you decide to Windows update your master image Win 7 (the one used by virtual snapshot) – you will be updating all components and services you keep. On top of that take into account that you can have 10 or more master images if you do not install different versions of the same browsers on the same master image. You will need to Windows Update all 10 if you care to have up-to-date Windows OS for testing. For us having a very minimal Windows image is crucial as, despite the fact that we use only one browser on one virtual machine during Selenium testing (so browsers do not overlap when screenshots are taken by tests), the actual VM will have all the browsers supported on this OS installed and only one version of each browser.
To illustrate, we have:
Xen VM_A – Windows XP IE8, FF 15.0, Opera 12.02, Safari 5.1.7, Chrome 21.0.1180
Xen VM_B – Windows XP IE8, FF 11.0, Opera 11.62 Safari 5.1.5, Chrome 20.0.1132
… and Nerrvana knows which one to snapshot and launch depending on the platforms you specified.
We do not have images like
Xen VM_C – Windows XP IE8 FF 15.0, Opera 12.02, Safari 5.1.7, Chrome 21.0.1180, FF 11.0, Opera 11.62 Safari 5.1.5, Chrome 20.0.1132
Because it takes a lot of time to figure out how to install, upgrade and launch different versions of the same browser on the same OS.
Black Viper has created a wonderful site where you will find a lot of useful and structured information about Windows components and services and their dependencies. For example, COM+ System Application. Notice the tabs below where you can view information about this component on Windows 8, 7, Vista, XP Pro x64 and XP.
Below I compared my services configuration setup and the Black Viper’s ‘bare-bones’ ones. Gray color marks those services which have been removed from the image of Windows. I loaded RT7 Lite with my last configuration file where these services are removed. If you are looking at this page before visiting ‘Features Removal’ tab then all the services here will be active (black).
A few words about the differences.
Background Intelligence Service – required for Windows Update. After updating, you can turn it off.
DNS client – according to the description “Only in extreme situations should you disable this service as caching DNS lookups reduces network traffic and makes internet surfing performance faster.”. It seemed important to keep it enabled.
Network Connections and Network List Service-responsible for displaying Network Connections in the Control Panel. I turned it off. If necessary, you can always turn on. I will not insist on keeping them disabled.
Themes – I left the service and keep it enabled because without it, the browser looks lame. If I am not mistaken it looks even worse than with disabled Visual Effects (more about the Visual Effects at the end of the post). Just check – switch it off on your computer and see yourself.
Windows Color System – probably agree with Black Viper – you can remove this service.
Windows Font Cache Service – “Optimizes performance of applications by caching commonly used font data. Applications will start this service if it is not already running. It can be disabled, though doing so will degrade application performance.” It seemed to me that a browser working with fonts will constantly start this service, and I left it enabled in the automatic mode. Perhaps Black Viper is right and it can be kept in Manual mode.
Windows Time – the ability to synchronize the time seemed to me as quite an important function to keep it and leave the service in Manual mode.
Windows Update – we keep it.
Startup types (Manual, Disabled, Automatic etc.) of Windows Services can be configured after OS installation. For example, after updating Windows you can disable the services responsible for updates – Windows Update, Windows Installer, Windows Modules Installer, Cryptographic Services and Background Intelligence Services. We do not want Windows checking or running updates when we run tests. It takes CPU, memory resources and fraught with unpredictable popups that may interfere with Selenium screenshots.
On the ‘Tweaks’ tab you can also change IE settings. I think it will be necessary to check if they are intact after upgrading from IE8 to IE9 – it’s not a given that they won’t be lost.

Now go to the ‘Features Removal’ tab. Look at ‘Default features’ in the most right section of the main window – as I understand it, list the components that will be present (if ticked) in the resulting image. I left only IE.
Below I present the results of my work. “Language Packs” have been cut out completely. In the section ‘Features to remove’ checked boxes mark components to be removed. Ticks in expandable checkboxes mean that all the components under them are also checked. Expandable boxes that are not checked I expanded in cases where not all of the components of the lower level left (not checked). For example – see ‘Display’ section below.
Finally, the last step – save customized image. If you want to save your settings and give the file a meaningful name, rather than relying on auto saving of RT7 Lite (it saves the file LastsessionX.inf adding a number in the order in the folder – C:\Program Files\Rockers Team\RT 7 Lite x64\Preset) – go back to the tab ‘Home’ and save the settings as indicated by the arrows below:

Now you can go to the ‘ISO-Bootable’ tab and save the results to the ISO file or burn it.

Since we are not going to install multiple times with this image, the further optimization can be carried out after installation. In all virtualization platforms there is cloning functionality, which allows you to create exact copies, work with them and fall back in case of an error during the manual customization process which will follow installation.
For more information on the further optimization of Windows 7 can be found for example here:
- Windows 7 – Optimize Windows 7
- Windows 7 – Visual Effects Settings. As for the option ‘Visual effects’, it is enough to keep only the ‘Smooth edges on screen fonts’ option, if you do not care how the browser’s frame will look (on your Selenium screenshots). Otherwise, add the ‘Use visual styles on windows and buttons’, and the browser will look like we used to see it.
Good luck!
Igor




