my computer keeps crashing?

my computer keeps freezing every 30 minutes and i have to restart my computer. i have xp media centre and avg internet security with the latest updates.

here is a hijackthis log

Platform: Windows XP SP3 (WinNT 5.01.2600)

MSIE: Internet Explorer v7.00 (7.00.6000.16735)

Boot mode: Normal

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\system32\spoolsv.exe

C:\Program Files\AskBarDis\bar\bin\AskService.exe

C:\PROGRA~1\AVG\AVG8\avgwdsvc.exe

C:\PROGRA~1\AVG\AVG8\avgfws8.exe

C:\Program Files\Belkin\Belkin Wireless Network Utility\WLService.exe

C:\Program Files\Belkin\Belkin Wireless Network Utility\WLanCfgG.exe

C:\WINDOWS\eHome\ehRecvr.exe

C:\WINDOWS\eHome\ehSched.exe

C:\WINDOWS\System32\svchost.exe

C:\Program Files\Java\jre6\bin\jqs.exe

C:\Program Files\Common Files\LightScribe\LSSrvc.exe

C:\Program Files\Common Files\Microsoft Shared\VS7DEBUG\MDM.EXE

C:\WINDOWS\system32\nvsvc32.exe

C:\WINDOWS\system32\svchost.exe

C:\WINDOWS\system32\SearchIndexer.exe

C:\PROGRA~1\AVG\AVG8\avgam.exe

C:\PROGRA~1\AVG\AVG8\avgrsx.exe

C:\PROGRA~1\AVG\AVG8\avgnsx.exe

C:\WINDOWS\system32\dllhost.exe

C:\WINDOWS\Explorer.EXE

C:\Program Files\Hewlett-Packard\HP Boot Optimizer\HPBootOp.exe

C:\Program Files\Hp\HP Software Update\HPWuSchd2.exe

C:\WINDOWS\RTHDCPL.EXE

C:\HP\KBD\KBD.EXE

C:\WINDOWS\ehome\ehtray.exe

C:\WINDOWS\eHome\ehmsas.exe

C:\Program Files\PC-Doctor 5 for Windows\PcdSmartMonitor.exe

C:\program files\common files\installshield\updateservice\issch.exe

C:\Program Files\Java\jre6\bin\jusched.exe

C:\PROGRA~1\AVG\AVG8\avgtray.exe

C:\WINDOWS\system32\ctfmon.exe

C:\Program Files\Windows Media Player\WMPNSCFG.exe

C:\Program Files\Windows Live\Messenger\msnmsgr.exe

C:\WINDOWS\system32\wuauclt.exe

C:\Program Files\Internet Explorer\iexplore.exe

C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

C:\Program Files\Common Files\Microsoft Shared\Windows Live\WLLoginProxy.exe

C:\WINDOWS\system32\SearchProtocolHost.exe

C:\WINDOWS\system32\SearchProtocolHost.exe

O1 - Hosts: 88.111.235.28 nellisere.dyndns.org

O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll

O2 - BHO: AskBar BHO - {201f27d4-3704-41d6-89c1-aa35e39143ed} - C:\Program Files\AskBarDis\bar\bin\askBar.dll

O2 - BHO: WormRadar.com IESiteBlocker.NavFilter - {3CA2F312-6F6E-4B53-A66E-4E65E497C8C0} - C:\Program Files\AVG\AVG8\avgssie.dll

O2 - BHO: Click-to-Call BHO - {5C255C8A-E604-49b4-9D64-90988571CECB} - C:\Program Files\Windows Live\Messenger\wlchtc.dll

O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre6\bin\ssv.dll

O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.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

O3 - Toolbar: Ask Toolbar - {3041d03e-fd4b-44e0-b742-2d9b88305f98} - C:\Program Files\AskBarDis\bar\bin\askBar.dll

O4 - HKLM\..\Run: [Recguard] C:\WINDOWS\SMINST\RECGUARD.EXE

O4 - HKLM\..\Run: [HPBootOp] "C:\Program Files\Hewlett-Packard\HP Boot Optimizer\HPBootOp.exe" /run

O4 - HKLM\..\Run: [PCDrSmartMonitor] "C:\Program Files\PC-Doctor 5 for Windows\PcdSmartMonitor.exe" -r

O4 - HKLM\..\Run: [HP Software Update] C:\Program Files\Hp\HP Software Update\HPWuSchd2.exe

O4 - HKLM\..\Run: [RTHDCPL] RTHDCPL.EXE

O4 - HKLM\..\Run: [Alcmtr] ALCMTR.EXE

O4 - HKLM\..\Run: [KBD] C:\HP\KBD\KBD.EXE

O4 - HKLM\..\Run: [Windows Media Connect 2] "C:\Program Files\Windows Media Connect 2\WMCCFG.exe" /StartQuiet

O4 - HKLM\..\Run: [ehTray] C:\WINDOWS\ehome\ehtray.exe

O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup

O4 - HKLM\..\Run: [ISUSPM Startup] C:\PROGRA~1\COMMON~1\INSTAL~1\UPDATE~1\ISUSPM.exe -startup

O4 - HKLM\..\Run: [ISUSScheduler] "c:\program files\common files\installshield\updateservice\issch.exe" -start

O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre6\bin\jusched.exe"

O4 - HKLM\..\Run: [AVG8_TRAY] C:\PROGRA~1\AVG\AVG8\avgtray.exe

O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe

O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe

O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\Windows Live\Messenger\msnmsgr.exe" /background

O4 - HKUS\S-1-5-19\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'LOCAL SERVICE')

O4 - HKUS\S-1-5-20\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'NETWORK SERVICE')

O4 - .DEFAULT User Startup: Pin.lnk = C:\hp\bi