Been having problems with the PC crashing over the last few months - but it's got really bad lately - a blue screen appears which says the following:

A problem has been detected and windows has been shut down to prevent damage to your computer

The problem seems to be caused by the following file: avg7core.sys

PAGE_FAULT_IN_NONPAGED_AREA

Then some more about "if this is the first time".....etc.

If you need more info on that I can post it, but I'd guess the main info needed is there - looks like something to do with the AVG anti virus? It also only seems to happen when I'm using Firefox - Been using IE for the last couple of hours and it's been fine. Previous to that, in Firefox, it crashed several times in an hour.

Hijack this log:

Logfile of HijackThis v1.99.1
Scan saved at 17:24:09, on 26/04/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

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:\WINDOWS\system32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\SOUNDMAN.EXE
C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe
C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
C:\Program Files\Multimedia Card Reader\shwicon2k.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
C:\Program Files\Java\jre1.6.0_03\bin\jusched.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
C:\Program Files\Common Files\Ahead\lib\NMBgMonitor.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
C:\WINDOWS\system32\ctfmon.exe
C:\WINDOWS\kdx\KHost.exe
C:\Program Files\Windows Media Player\WMPNSCFG.exe
C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\KService\KService.exe
C:\Program Files\Common Files\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\WINDOWS\system32\HPZipm12.exe
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\Program Files\Canon\CAL\CALMAIN.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\HijackThis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.cpfc.premiumtv.co.uk/page/Welcome
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://uk.rd.yahoo.com/customize/ie/defaults/su/msgr8/*http://uk.search.yahoo.com
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyServer = webcache.blueyonder.co.uk:8080
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - 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: SpywareGuardDLBLOCK.CBrowserHelper - {4A368E80-174F-4872-96B5-0B27DDD11DB2} - C:\Program Files\SpywareGuard\dlprotect.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_03\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [ATIPTA] C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [WinPatrol] C:\Program Files\BillP Studios\WinPatrol\winpatrol.exe
O4 - HKLM\..\Run: [HP Software Update] C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [Sunkist2k] C:\Program Files\Multimedia Card Reader\shwicon2k.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_03\bin\jusched.exe"
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [Adobe Photo Downloader] "C:\Program Files\Adobe\Photoshop Album Starter Edition\3.2\Apps\apdproxy.exe"
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKCU\..\Run: [BgMonitor_{79662E04-7C6C-4d9f-84C7-88D8A56B10AA}] "C:\Program Files\Common Files\Ahead\lib\NMBgMonitor.exe"
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [kdx] C:\WINDOWS\kdx\KHost.exe -all
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - Startup: MRU-Blaster Scheduler.lnk = C:\Program Files\MRU-Blaster\scheduler.exe
O4 - Startup: MRU-Blaster Silent Clean.lnk = C:\Program Files\MRU-Blaster\mrublaster.exe
O4 - Startup: SpywareGuard.lnk = C:\Program Files\SpywareGuard\sgmain.exe
O4 - Global Startup: HP Digital Imaging Monitor.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_03\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_03\bin\ssv.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
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: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Program Files\Yahoo!\Common\yinsthelper.dll
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/microsoftupdate/v6/V5Controls/en/x86/client/muweb_site.cab?1136832220828
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O21 - SSODL: WPDShServiceObj - {AAA288BA-9A4C-45B0-95D7-94D524869DB5} - C:\WINDOWS\system32\WPDShServiceObj.dll
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
O23 - Service: AVG E-mail Scanner (AVGEMS) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
O23 - Service: Canon Camera Access Library 8 (CCALib8) - Canon Inc. - C:\Program Files\Canon\CAL\CALMAIN.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\1150\Intel 32\IDriverT.exe
O23 - Service: iPod Service - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: KService - Kontiki Inc. - C:\Program Files\KService\KService.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe
O23 - Service: Sunbelt Personal Firewall 4 (SPF4) - Sunbelt Software - C:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe