The Dell Dimension 8400 shuts down unexpectedly, leaving the start button flashing amber, with lights still on the keyboard.
Other symptoms:  colours have changed and are not set up as they normally look.  We are unable to correct the colours.  The shape of the screen is distorted and smaller than normal.  Icons in desktop folders have been rearranged.  Screensaver slide-show was changed to Windows XP screensaver - this we were able to fix.

We are using Sophos and have run other malware programs and no virus or malware was found.

Following is the Hijack This Log.

Logfile of HijackThis v1.99.1
Scan saved at 8:10:49 PM, on 02/12/2010
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.17091)

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\System32\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\LEXBCES.EXE
C:\Program Files\Sophos\Sophos Client Firewall\SCFManager.exe
C:\WINDOWS\system32\LEXPPS.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Sophos\Sophos Client Firewall\SCFService.exe
C:\Program Files\Intel\Modem Event Monitor\IntelMEM.exe
C:\WINDOWS\system32\dla\tfswctrl.exe
C:\Program Files\Dell AIO Printer A920\dlbkbmgr.exe
C:\Program Files\Dell Support Center\bin\sprtcmd.exe
C:\Program Files\Dell\Media Experience\PCMService.exe
C:\Program Files\Sophos\Sophos Client Firewall\SCFTray.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Ahead\ODD Toolkit\DVDTray.exe
C:\Program Files\Common Files\Java\Java Update\jusched.exe
C:\Program Files\DellSupport\DSAgnt.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Dell AIO Printer A920\dlbkbmon.exe
C:\Program Files\Sophos\AutoUpdate\ALMon.exe
C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
C:\Program Files\Classic PhoneTools\Phontool.exe
C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
C:\Program Files\Bonjour\mDNSResponder.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Intel\Intel Application Accelerator\iaantmon.exe
C:\Program Files\Java\jre6\bin\jqs.exe
C:\Program Files\Common Files\LightScribe\LSSrvc.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Sophos\Sophos Anti-Virus\SAVAdminService.exe
C:\Program Files\Sophos\AutoUpdate\ALsvc.exe
C:\Program Files\Dell Support Center\bin\sprtsvc.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\HP\Digital Imaging\bin\hpqSTE08.exe
C:\Program Files\HP\Digital Imaging\bin\hpqbam08.exe
C:\Program Files\HP\Digital Imaging\bin\hpqgpc01.exe
C:\WINDOWS\System32\svchost.exe
C:\hijackthis\analyzer.exe.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.dell.com
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.ca/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://ca.search.yahoo.com/search?fr=mcafee&p=%s
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
O2 - BHO: HP Print Enhancer - {0347C33E-8762-4905-BF09-768834316C61} - C:\Program Files\HP\Digital Imaging\Smart Web Printing\hpswp_printenhancer.dll
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Sophos Web Content Scanner - {39EA7695-B3F2-4C44-A4BC-297ADA8FD235} - C:\Program Files\Sophos\Sophos Anti-Virus\SophosBHO.dll
O2 - BHO: WormRadar.com IESiteBlocker.NavFilter - {3CA2F312-6F6E-4B53-A66E-4E65E497C8C0} - C:\Program Files\AVG\AVG8\avgssie.dll (file missing)
O2 - BHO: DriveLetterAccess - {5CA3D70E-1895-11CF-8E15-001234567890} - C:\WINDOWS\system32\dla\tfswshx.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O2 - BHO: JQSIEStartDetectorImpl - {E7E6F031-17CE-4C07-BC86-EABFE594F69C} - C:\Program Files\Java\jre6\lib\deploy\jqs\ie\jqs_plugin.dll
O2 - BHO: HP Smart BHO Class - {FFFFFFFF-CF4E-4F2B-BDC2-0E72E116A856} - C:\Program Files\HP\Digital Imaging\Smart Web Printing\hpswp_BHO.dll
O4 - HKLM\..\Run: [IAAnotif] C:\Program Files\Intel\Intel Application Accelerator\iaanotif.exe
O4 - HKLM\..\Run: [IntelMeM] C:\Program Files\Intel\Modem Event Monitor\IntelMEM.exe
O4 - HKLM\..\Run: [dla] C:\WINDOWS\system32\dla\tfswctrl.exe
O4 - HKLM\..\Run: [UpdateManager] "C:\Program Files\Common Files\Sonic\Update Manager\sgtray.exe" /r
O4 - HKLM\..\Run: [Dell AIO Printer A920] "C:\Program Files\Dell AIO Printer A920\dlbkbmgr.exe"
O4 - HKLM\..\Run: [dscactivate] "C:\Program Files\Dell Support Center\gs_agent\custom\dsca.exe"
O4 - HKLM\..\Run: [DellSupportCenter] "C:\Program Files\Dell Support Center\bin\sprtcmd.exe" /P DellSupportCenter
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [osCheck] "C:\Program Files\Norton Internet Security\osCheck.exe"
O4 - HKLM\..\Run: [PCMService] "C:\Program Files\Dell\Media Experience\PCMService.exe"
O4 - HKLM\..\Run: [SCFTrayStartUp] C:\Program Files\Sophos\Sophos Client Firewall\SCFTray.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [DVDTray] C:\Program Files\Ahead\ODD Toolkit\DVDTray.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Common Files\Java\Java Update\jusched.exe"
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 9.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [Adobe ARM] "C:\Program Files\Common Files\Adobe\ARM\1.0\AdobeARM.exe"
O4 - HKCU\..\Run: [DellSupport] "C:\Program Files\DellSupport\DSAgnt.exe" /startup
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [DellSupportCenter] "C:\Program Files\Dell Support Center\bin\sprtcmd.exe" /P DellSupportCenter
O4 - Startup: Classic PhoneTools.lnk = C:\Program Files\Classic PhoneTools\Phontool.exe
O4 - Global Startup: AutoUpdate Monitor.lnk = C:\Program Files\Sophos\AutoUpdate\ALMon.exe
O4 - Global Startup: HP Digital Imaging Monitor.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office\OSA9.EXE
O9 - Extra button: MUSICMATCH MX Web Player - {d81ca86b-ef63-42af-bee3-4502d9a03c2d} - http://wwws.musicmatch.com/mmz/openWebRadio.html (file missing)
O9 - Extra button: Show or hide HP Smart Web Printing - {DDE87865-83C5-48c4-8357-2F5B1AA84522} - C:\Program Files\HP\Digital Imaging\Smart Web Printing\hpswp_BHO.dll
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O10 - Unknown file in Winsock LSP: c:\program files\bonjour\mdnsnsp.dll
O11 - Options group: [INTERNATIONAL] International*
O16 - DPF: {076169AA-8C3D-4CFC-AC23-3ACA88FC21B5} (F-Secure Online Scanner Launcher) - http://download.sp.f-secure.com/ols/f-secure-rtm/resources/fslauncher.cab
O16 - DPF: {215B8138-A3CF-44C5-803F-8226143CFC0A} (Trend Micro ActiveX Scan Agent 6.6) - http://housecall65.trendmicro.com/housecall/applet/html/native/x86/win32/activex/hcImpl.cab
O16 - DPF: {238F6F83-B8B4-11CF-8771-00A024541EE3} (Citrix ICA Client) - https://csg.shin.sk.ca/hisc/cds/ICAWEB/en/ica32/ica32t.exe
O16 - DPF: {2D8ED06D-3C30-438B-96AE-4D110FDC1FB8} (ActiveScan 2.0 Installer Class) - http://acs.pandasoftware.com/activescan/cabs/as2stubie.cab
O16 - DPF: {56762DEC-6B0D-4AB4-A8AD-989993B5D08B} (OnlineScanner Control) - http://www.eset.eu/buxus/docs/OnlineScanner.cab
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/SharedContent/common/bin/cabsa.cab
O16 - DPF: {6A344D34-5231-452A-8A57-D064AC9B7862} (Symantec Download Manager) - https://webdl.symantec.com/activex/symdlmgr.cab
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/microsoftupdate/v6/V5Controls/en/x86/client/muweb_site.cab?1143389526093
O16 - DPF: {7530BFB8-7293-4D34-9923-61A11451AFC5} (OnlineScanner Control) - http://download.eset.com/special/eos/OnlineScanner.cab
O16 - DPF: {9191F686-7F0A-441D-8A98-2FE3AC1BD913} (ActiveScan 2.0 Installer Class) - http://acs.pandasoftware.com/activescan/cabs/as2stubie.cab
O16 - DPF: {B1826A9F-4AA0-4510-BA77-9013E74E4B9B} - http://www.trendmicro.com/spyware-scan/as4web.cab
O16 - DPF: {BDBDE413-7B1C-4C68-A8FF-C5B2B4090876} (F-Secure Online Scanner 3.3) - http://support.f-secure.com/ols/fscax.cab
O16 - DPF: {C237A80A-4C55-4C68-BAA9-CBE4408D12B2} (F-Secure Online Scanner 4.0 Launcher) - http://download.sp.f-secure.com/ols/f-secure-rtm/resources/fslauncher.cab
O16 - DPF: {CAFEEFAC-0016-0000-0000-ABCDEFFEDCBA} (Java Plug-in 1.6.0) -
O16 - DPF: {CAFEEFAC-0016-0000-0001-ABCDEFFEDCBA} (Java Plug-in 1.6.0_01) -
O16 - DPF: {CAFEEFAC-0016-0000-0002-ABCDEFFEDCBA} (Java Plug-in 1.6.0_02) -
O16 - DPF: {CAFEEFAC-0016-0000-0003-ABCDEFFEDCBA} (Java Plug-in 1.6.0_03) -
O16 - DPF: {CAFEEFAC-0016-0000-0005-ABCDEFFEDCBA} (Java Plug-in 1.6.0_05) -
O16 - DPF: {CAFEEFAC-0016-0000-0007-ABCDEFFEDCBA} (Java Plug-in 1.6.0_07) -
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O16 - DPF: {E06E2E99-0AA1-11D4-ABA6-0060082AA75C} (GpcContainer Class) - https://shin.webex.com/client/T26L/support/ieatgpc.cab
O16 - DPF: {E2883E8F-472F-4FB0-9522-AC9BF37916A7} - http://platformdl.adobe.com/NOS/getPlusPlus/1.6/gp.cab
O16 - DPF: {EBC1356E-7D5E-44EC-831D-847882F06FE5} (Gateway Client for MetaFrame) - https://csg.shin.sk.ca/hisc/cds/CGC/en/CSGProxy.cab
O16 - DPF: {F27237D7-93C8-44C2-AC6E-D6057B9A918F} (JuniperSetupClientControl Class) - https://juniper.net/dana-cached/sc/JuniperSetupClient.cab
O20 - AppInit_DLLs: c:\PROGRA~1\Sophos\SOPHOS~1\SOPHOS~1.DLL
O20 - Winlogon Notify: !SASWinLogon - C:\Program Files\SUPERAntiSpyware\SASWINLO.dll
O20 - Winlogon Notify: dimsntfy - %SystemRoot%\System32\dimsntfy.dll (file missing)
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O21 - SSODL: WPDShServiceObj - {AAA288BA-9A4C-45B0-95D7-94D524869DB5} - C:\WINDOWS\system32\WPDShServiceObj.dll
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: Bonjour Service - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: DSBrokerService - Unknown owner - C:\Program Files\DellSupport\brkrsvc.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: IAA Event Monitor (IAANTMon) - Intel Corporation - C:\Program Files\Intel\Intel Application Accelerator\iaantmon.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: iPod Service - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Java Quick Starter (JavaQuickStarterService) - Unknown owner - C:\Program Files\Java\jre6\bin\jqs.exe" -service -config "C:\Program Files\Java\jre6\lib\deploy\jqs\jqs.conf (file missing)
O23 - Service: LexBce Server (LexBceS) - Lexmark International, Inc. - C:\WINDOWS\system32\LEXBCES.EXE
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Common Files\LightScribe\LSSrvc.exe
O23 - Service: Sophos Anti-Virus status reporter (SAVAdminService) - Sophos Plc - C:\Program Files\Sophos\Sophos Anti-Virus\SAVAdminService.exe
O23 - Service: Sophos Anti-Virus (SAVService) - Sophos Plc - C:\Program Files\Sophos\Sophos Anti-Virus\SavService.exe
O23 - Service: Sophos AutoUpdate Service - Unknown owner - C:\Program Files\Sophos\AutoUpdate\ALsvc.exe" (file missing)
O23 - Service: Sophos Client Firewall - Sophos Plc - C:\Program Files\Sophos\Sophos Client Firewall\SCFService.exe
O23 - Service: Sophos Client Firewall Manager - Sophos Plc - C:\Program Files\Sophos\Sophos Client Firewall\SCFManager.exe
O23 - Service: SupportSoft Sprocket Service (dellsupportcenter) (sprtsvc_dellsupportcenter) - SupportSoft, Inc. - C:\Program Files\Dell Support Center\bin\sprtsvc.exe