Why am I getting a 0x0000007f (0x7f) STOP error code / Blue Screen of Death when I try to boot XP Pro SP2 in Normal mode, but not Safe mode?

The computer in question is a Dell Dimension 9200, Core 2 Duo 6600 @ 2.4GHz. 1 GB RAM (2 x 512 MB DIMMs). The OS is Windows XP Pro w/SP2.

The problem started a few days ago for no apparent reason. The user complained of the computer shutting down suddenly with a flash of a blue screen.

When I try to boot the PC into Normal mode (or Last Known Good Config), it gets to the Windows loading screen, then the blank, light blue screen with the mouse for about 3-5 seconds, then it blue screens. Even though "automatic restart after system failure" is disabled, the blue screen lasts for about half a second.

The error message is "The computer has rebooted from a bugcheck.  The bugcheck was: 0x1000007f (0x00000008, 0x80042000, 0x00000000, 0x00000000)."
(The error code is 0x0000007f in the blue screen itself, not 0x1000007f).
I looked up 0x7f and most sites said it was a hardware problem. I ran Dell's hardware diagnostics utility and it came up with no problems. Memtest86 showed no problems. I swapped the sticks of RAM, tried with just one in, and the other in, and tried the different set of memory slots. All produced the same problem. I downloaded and installed the latest Intel Chipset drivers, and tried to install the latest BIOS update, but it wouldn't let me in Safe mode.

I also tried in VGA mode, to see if it was video card driver-related, but I get the same exact blue screen at the same point.

I can load XP all the way in Safe Mode w/Networking just fine, no blue/STOP screens, everything [that Safe Mode loads] is functional. Spybot 1.6 w/latest definitions (as of 2008-09-02) detected Antivirus XP 2008, and My Web Search, and a couple other things (CouponBar, can't remember the rest, but they seemed fairly benign, like cookies, registry entries). I removed these and now Spybot is reporting nothing, but I still get the blue screen when I try to boot in normal mode.

So the fact that I can boot up and run the PC just fine in Safe Mode w/Networking suggests the problem lies with some piece of software or .dll or .exe or driver that is loading in Normal Mode but not Safe Mode... rather than a motherboard/processor (which is not overclocked, by the way) issue.

Symantec AV Corporate Edition (latest definitions) is installed on this computer, as is Acrobat 8 Pro, and Peachtree accounting software.

Here's the log of the latest HiJackThis! scan (disregard the DOMAIN-REMOVED.com, that's because this PC is on a Windows Server 2003 Active Directory domain, and I renamed the domain for privacy purposes ---- also, Spybot removed several things but apparently has to boot into Normal Mode to delete the last remnants, which it can't do because I can't get into Normal mode, but I already removed these items manually -- so that's why it says "SpybotDeleting"):

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 4:23:43 PM, on 9/2/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16705)
Boot mode: Safe mode with network support

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\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Lavasoft\Ad-Aware\aawservice.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Internet Explorer\iexplore.exe
C:\WINDOWS\system32\ctfmon.exe
C:\WINDOWS\system32\mmc.exe
C:\Program Files\Spybot - Search & Destroy\SpybotSD.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://smbusiness.dellnet.com/
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://google.com/
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 - HKLM\Software\Microsoft\Internet Explorer\Search,Default_Page_URL = www.google.com/ig/dell?hl=en&client=dell-usuk-rel&channel=us&ibd=1061027
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyServer = :0
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O1 - Hosts: 199.41.56.5 dcsprod.phx-dc.dhl.com # port 7000 ICS production host
O1 - Hosts: 199.41.254.207 xmlpi.dhl-usa.com # port 80 XML services for tracking
O1 - Hosts: 199.41.238.32 www.dhl-usa.com # port 80 www.dhl-usa.com for services
O1 - Hosts: 199.41.254.110 dhlconnect.dhl-usa.com # port 80 AWB range request HTTP server
O1 - Hosts: 199.41.238.52 track.dhl-usa.com
O1 - Hosts: 199.41.238.63 webship.dhl-usa.com
O1 - Hosts: 65.114.156.130 aesdirect.gov
O1 - Hosts: 65.114.156.130 www.aesdirect.gov
O1 - Hosts: 199.41.254.163 xmlshippingtest.dhl-usa.com
O2 - BHO: &Yahoo! Toolbar Helper - {02478D38-C3F9-4efb-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.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: DriveLetterAccess - {5CA3D70E-1895-11CF-8E15-001234567890} - C:\WINDOWS\System32\DLA\DLASHX_W.DLL
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_05\bin\ssv.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar1.dll
O2 - BHO: Adobe PDF Conversion Toolbar Helper - {AE7CD045-E861-484f-8273-0445EE161910} - C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\3.0.1225.9868\swg.dll
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar1.dll
O3 - Toolbar: Adobe PDF - {47833539-D0C5-4125-9FA8-0819E2EAAC93} - C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [Synchronization Manager] %SystemRoot%\system32\mobsync.exe /logon
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_05\bin\jusched.exe"
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [vptray] C:\PROGRA~1\SYMANT~1\VPTray.exe
O4 - HKLM\..\Run: [PeachtreePrefetcher.exe] "C:\PROGRA~1\SAGESO~1\PEACHT~1\PeachtreePrefetcher.exe" /configfile:peachtreeprefetcher.winstart.config
O4 - HKLM\..\Run: [AppleSyncNotifier] C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleSyncNotifier.exe
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKLM\..\RunOnce: [wdl] C:\Program Files\Dell\Chipset Software Installer\setup.exe -S
O4 - HKLM\..\RunOnce: [SpybotDeletingA4985] command /c del "C:\Documents and Settings\All Users\Start Menu\Programs\Antivirus XP 2008\Register Antivirus XP 2008.lnk"
O4 - HKLM\..\RunOnce: [SpybotDeletingC8993] cmd /c del "C:\Documents and Settings\All Users\Start Menu\Programs\Antivirus XP 2008\Register Antivirus XP 2008.lnk"
O4 - HKLM\..\RunOnce: [SpybotDeletingA2516] command /c del "C:\WINDOWS\system32\CbEvtSvc.exe"
O4 - HKLM\..\RunOnce: [SpybotDeletingC8824] cmd /c del "C:\WINDOWS\system32\CbEvtSvc.exe"
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [Steam] "c:\program files\steam\steam.exe" -silent
O4 - HKCU\..\Run: [EPSON Stylus CX9400Fax Series] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATICFA.EXE /FU "C:\WINDOWS\TEMP\E_S6EB.tmp" /EF "HKCU"
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
O4 - HKCU\..\RunOnce: [SpybotDeletingB5678] command /c del "C:\Documents and Settings\All Users\Start Menu\Programs\Antivirus XP 2008\Register Antivirus XP 2008.lnk"
O4 - HKCU\..\RunOnce: [SpybotDeletingD1094] cmd /c del "C:\Documents and Settings\All Users\Start Menu\Programs\Antivirus XP 2008\Register Antivirus XP 2008.lnk"
O4 - HKCU\..\RunOnce: [SpybotDeletingB2453] command /c del "C:\WINDOWS\system32\CbEvtSvc.exe"
O4 - HKCU\..\RunOnce: [SpybotDeletingD1768] cmd /c del "C:\WINDOWS\system32\CbEvtSvc.exe"
O4 - Global Startup: Google Updater.lnk = C:\Program Files\Google\Google Updater\GoogleUpdater.exe
O4 - Global Startup: Service Manager.lnk = C:\Program Files\Microsoft SQL Server\80\Tools\Binn\sqlmangr.exe
O8 - Extra context menu item: &Google Search - res://C:\Program Files\Google\GoogleToolbar1.dll/cmsearch.html
O8 - Extra context menu item: &Translate English Word - res://C:\Program Files\Google\GoogleToolbar1.dll/cmwordtrans.html
O8 - Extra context menu item: Append to existing PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIEAppend.html
O8 - Extra context menu item: Backward Links - res://C:\Program Files\Google\GoogleToolbar1.dll/cmbacklinks.html
O8 - Extra context menu item: Cached Snapshot of Page - res://C:\Program Files\Google\GoogleToolbar1.dll/cmcache.html
O8 - Extra context menu item: Convert link target to Adobe PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIECapture.html
O8 - Extra context menu item: Convert link target to existing PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIEAppend.html
O8 - Extra context menu item: Convert selected links to Adobe PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIECaptureSelLinks.html
O8 - Extra context menu item: Convert selected links to existing PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIEAppendSelLinks.html
O8 - Extra context menu item: Convert selection to Adobe PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIECapture.html
O8 - Extra context menu item: Convert selection to existing PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIEAppend.html
O8 - Extra context menu item: Convert to Adobe PDF - res://C:\Program Files\Adobe\Acrobat 8.0\Acrobat\AcroIEFavClient.dll/AcroIECapture.html
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Similar Pages - res://C:\Program Files\Google\GoogleToolbar1.dll/cmsimilar.html
O8 - Extra context menu item: Translate Page into English - res://C:\Program Files\Google\GoogleToolbar1.dll/cmtrans.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_05\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_05\bin\ssv.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
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
O16 - DPF: {4871A87A-BFDD-4106-8153-FFDE2BAC2967} (DLM Control) - http://dlm.tools.akamai.com/dlmanager/versions/activex/dlm-activex-2.2.3.5.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O17 - HKLM\System\CCS\Services\Tcpip\Parameters: Domain = DOMAIN-REMOVED.com
O17 - HKLM\Software\..\Telephony: DomainName = DOMAIN-REMOVED.com
O17 - HKLM\System\CS1\Services\Tcpip\Parameters: Domain = DOMAIN-REMOVED.com
O21 - SSODL: QWdraQm - {6CB65C17-C61C-F6BD-1EC9-B8DE7FF130DD} - C:\WINDOWS\system32\wijl.dll
O23 - Service: Lavasoft Ad-Aware Service (aawservice) - Lavasoft - C:\Program Files\Lavasoft\Ad-Aware\aawservice.exe
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: Bonjour Service - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
O23 - Service: Symantec AntiVirus Definition Watcher (DefWatch) - Symantec Corporation - C:\Program Files\Symantec AntiVirus\DefWatch.exe
O23 - Service: FLEXnet Licensing Service - Macrovision Europe Ltd. - C:\Program Files\Common Files\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: Intel(R) Matrix Storage Event Monitor (IAANTMON) - Intel Corporation - C:\Program Files\Intel\Intel Matrix Storage Manager\Iaantmon.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\1050\Intel 32\IDriverT.exe
O23 - Service: iPod Service - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: LiveUpdate - Symantec Corporation - C:\PROGRA~1\Symantec\LIVEUP~1\LUCOMS~1.EXE
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: SAVRoam (SavRoam) - symantec - C:\Program Files\Symantec AntiVirus\SavRoam.exe
O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
O23 - Service: Symantec SPBBCSvc (SPBBCSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SPBBC\SPBBCSvc.exe
O23 - Service: Symantec AntiVirus - Symantec Corporation - C:\Program Files\Symantec AntiVirus\Rtvscan.exe

--
End of file - 12040 bytes