when i try to install any program i have downloaded i get a NSIS Error. this is wat it says:
"NSIS Error
The installer you are trying to use is corrupted or incomplete
This could be the result of a damaged disk, a failed download or a virus
it may be possible to skip this check using the /NCRC command line switch (not recommended)"

anyone know how to fix this. please help

i am running windows xp home, SP2

this is a coppy of my hijackthis log:

Logfile of HijackThis v1.99.1
Scan saved at 9:32:04 AM, on 4/12/2005
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:\Program Files\Ahead\InCD\InCDsrv.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Common Files\Symantec Shared\ccProxy.exe
C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
C:\Program Files\Norton Internet Security\ISSVC.exe
C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
C:\Program Files\Common Files\Symantec Shared\SPBBC\SPBBCSvc.exe
C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\CTsvcCDA.exe
C:\Program Files\NVIDIA Corporation\NetworkAccessManager\Apache Group\Apache2\bin\apache.exe
C:\Program Files\Common Files\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\Program Files\Norton Internet Security\Norton AntiVirus\navapsvc.exe
C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin\nSvcIp.exe
C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin\nSvcLog.exe
C:\WINDOWS\system32\nvsvc32.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\MsPMSPSv.exe
C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin\nSvcAppFlt.exe
C:\Program Files\NVIDIA Corporation\NetworkAccessManager\Apache Group\Apache2\bin\apache.exe
C:\Program Files\Common Files\Symantec Shared\ccApp.exe
C:\program files\valve\steam\steam.exe
C:\Program Files\Messenger\msmsgs.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Logitech\SetPoint\KEM.exe
C:\Program Files\Logitech\SetPoint\KHALMNPR.EXE
C:\Documents and Settings\Me\Desktop\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://runescape.com/
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: iMeshBar BHO - {5345A7A1-805A-4923-B505-86B2FEBA3FE0} - C:\Program Files\iMeshBar\bar\1.bin\IMESHBAR.DLL
O2 - BHO: ST - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Program Files\MSN Apps\ST\01.03.0000.1005\en-xu\stmain.dll
O2 - BHO: Norton Internet Security - {9ECB9560-04F9-4bbc-943D-298DDF1699E1} - C:\Program Files\Common Files\Symantec Shared\AdBlocking\NISShExt.dll
O2 - BHO: MSNToolBandBHO - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.4000.1001\en-au\msntb.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Program Files\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: Norton Internet Security - {0B53EAC3-8D69-4b9e-9B19-A37C9A5676A7} - C:\Program Files\Common Files\Symantec Shared\AdBlocking\NISShExt.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Program Files\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: ninemsn - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.4000.1001\en-au\msntb.dll
O3 - Toolbar: iMeshBar - {5345A7A9-805A-4923-B505-86B2FEBA3FE0} - C:\Program Files\iMeshBar\bar\1.bin\IMESHBAR.DLL
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [URLLSTCK.exe] C:\Program Files\Norton Internet Security\UrlLstCk.exe
O4 - HKLM\..\Run: [UpdReg] C:\WINDOWS\UpdReg.EXE
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKCU\..\Run: [Steam] "c:\program files\valve\steam\steam.exe" -silent
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - Global Startup: Logitech SetPoint.lnk = C:\Program Files\Logitech\SetPoint\KEM.exe
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~3\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\j2re1.4.2_04\bin\npjpi142_04.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\j2re1.4.2_04\bin\npjpi142_04.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\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
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\nvappfilter.dll
O16 - DPF: {00B71CFB-6864-4346-A978-C0A14556272C} (Checkers Class) - http://messenger.zone.msn.com/binary/msgrchkr.cab31267.cab
O16 - DPF: {14B87622-7E19-4EA8-93B3-97215F77A6BC} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab31267.cab
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsClient.cab31267.cab
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/MsnMessengerSetupDownloader.cab
O16 - DPF: {B8BE5E93-A60C-4D26-A2DC-220313175592} (ZoneIntro Class) - http://messenger.zone.msn.com/binary/ZIntro.cab32846.cab
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - "C:\PROGRA~1\MSNMES~1\msgrapp.dll" (file missing)
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Network Proxy (ccProxy) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccProxy.exe
O23 - Service: Symantec Password Validation (ccPwdSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccPwdSvc.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
O23 - Service: Creative Service for CDROM Access - Creative Technology Ltd - C:\WINDOWS\system32\CTsvcCDA.exe
O23 - Service: ForceWare Intelligent Application Manager (IAM) - Unknown owner - C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin\nSvcAppFlt.exe
O23 - Service: Forceware Web Interface (ForcewareWebInterface) - Unknown owner - C:\Program Files\NVIDIA Corporation\NetworkAccessManager\Apache Group\Apache2\bin\apache.exe" -k runservice (file missing)
O23 - Service: InCD Helper (InCDsrv) - Ahead Software AG - C:\Program Files\Ahead\InCD\InCDsrv.exe
O23 - Service: ISSvc (ISSVC) - Symantec Corporation - C:\Program Files\Norton Internet Security\ISSVC.exe
O23 - Service: Norton AntiVirus Auto-Protect Service (navapsvc) - Symantec Corporation - C:\Program Files\Norton Internet Security\Norton AntiVirus\navapsvc.exe
O23 - Service: ForceWare IP service (nSvcIp) - NVIDIA - C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin\nSvcIp.exe
O23 - Service: ForceWare user log service (nSvcLog) - NVIDIA - C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin\nSvcLog.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe
O23 - Service: SAVScan - Symantec Corporation - C:\Program Files\Norton Internet Security\Norton AntiVirus\SAVScan.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\COMMON~1\SYMANT~1\SCRIPT~1\SBServ.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