Big problems

I've been having a problem for about a month now. It all started when AVG antivirus starting having problems loading different things. One time it was the virus database. So I had to uninstall and re-install, and everything was fine. For about two days. Then it did the same problem again. So I had to uninstall and re-install again, and everything was fine. I also started having problems with Mozilla Firefox. It would start crashing. I unistalled and reinstalled it also and it hasn't fixed any problems. It still runs but crashed often. Now i can't run AVG 7.5. I can't even uninstall the program any more. I've tried installing other virus programs and they failed on install. I tried to do a system restore and all four times they failed. My ad aware virus definitions will no longer load and I can not update them. I tried to use an online virus scanner. It kept having errors. Finally on a third try it was working. Half-way through the scan Firefox just shut down without and error message at all. After re-started firefox it didn't even acknowledge that it had an error and had to be shut down previously. I thought I took good care of computer. I guess I was wrong. Can anyone help me?

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 7:11:19 PM, on 12/20/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16574)
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\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\devldr32.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\ctfmon.exe
C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Common Files\Microsoft Shared\VS7Debug\mdm.exe
C:\WINDOWS\system32\pctspk.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Zune\ZuneNss.exe
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\Windows Media Player\WMPNSCFG.exe
C:\Documents and Settings\Jay\Desktop\HiJackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://us.rd.yahoo.com/customize/ie/defaul…rch/search.html
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = about:blank
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 Bar = http://us.rd.yahoo.com/customize/ie/defaul…rch/search.html
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
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://channels.aimtoday.com/search/aimtoolbar.jsp
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://us.rd.yahoo.com/customize/ie/defaul…//www.yahoo.com
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://www.dell.com/corporate
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O4 - HKLM\..\Run: [UserFaultCheck] %systemroot%\system32\dumprep 0 -u
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - HKUS\S-1-5-19\..\Run: [AVG7_Run] C:\PROGRA~1\Grisoft\AVG7\avgw.exe /RUNONCE (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-20\..\Run: [AVG7_Run] C:\PROGRA~1\Grisoft\AVG7\avgw.exe /RUNONCE (User 'NETWORK SERVICE')
O4 - HKUS\S-1-5-18\..\Run: [MySpaceIM] C:\Program Files\MySpace\IM\MySpaceIM.exe (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [MySpaceIM] C:\Program Files\MySpace\IM\MySpaceIM.exe (User 'Default user')
O8 - Extra context menu item: &AOL Toolbar search - res://C:\Program Files\AOL Toolbar\toolbar.dll/SEARCH.HTML
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra button: AIM - {AC9E2541-2814-11d5-BC6D-00B0D0A1DE45} - C:\Program Files\AIM\aim.exe
O9 - Extra button: Real.com - {CD67F990-D8E9-11d2-98FE-00C0F0318AFE} - C:\WINDOWS\System32\Shdocvw.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: {01A88BB1-1174-41EC-ACCB-963509EAE56B} (SysProWmi Class) - http://support.dell.com/systemprofiler/SysPro.CAB
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) -
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://v5.windowsupdate.microsoft.com/v5co…b?1096529594687
O16 - DPF: {94B82441-A413-4E43-8422-D49930E69764} (TLIEFlashObj Class) - https://webchat.dell.com/Media/VisitorChat/TLIEFlash.CAB
O23 - Service: Adobe LM Service - Unknown owner - C:\Program Files\Common Files\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe
O23 - Service: AVG E-mail Scanner (AVGEMS) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgemc.exe
O23 - Service: NBService - Nero AG - C:\Program Files\Nero\Nero 7\Nero BackItUp\NBService.exe
O23 - Service: Intel NCS NetService (NetSvc) - Intel® Corporation - C:\Program Files\Intel\PROSetWired\NCS\Sync\NetSvc.exe
O23 - Service: NMIndexingService - Nero AG - C:\Program Files\Common Files\Ahead\Lib\NMIndexingService.exe
O23 - Service: PCTEL Speaker Phone (Pctspk) - PCtel, Inc. - C:\WINDOWS\system32\pctspk.exe
O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe

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