Trouble with NAV / NIS install (missing ccRegvfy.exe?)

according to what I've been able to determine from Norton's site, NIS didn't install correctly on my system because some services, including ccRegVfy.exe didn't load properly. When I try and use there automated assistant to check my NAV (installed alongside NIS), the browser closes. I've been struggling with this system after many viruses were cleaned from it, and I'm pretty sure it's now virus free. I ran housecall on it and norton's on-line scanner. However, NIS won't install properly, that's the root of my worries. I've done an XP install in place, because I messed up the registry at one point trying to uninstall NIS completely in order to reinstall. I'm pretty sure i'm in the middle of one of those Norton Horror Stories that people often talk about. Where's the end? Sigh.

Here's my HijackThis log.

Logfile of HijackThis v1.97.7
Scan saved at 2:03:00 AM, on 6/8/2004
Platform: Windows XP SP1 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

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\Explorer.EXE
C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Common Files\Symantec Shared\ccApp.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\Common Files\Symantec Shared\ccProxy.exe
C:\Program Files\Norton Internet Security\Norton AntiVirus\navapsvc.exe
C:\Program Files\Norton Internet Security\Norton AntiVirus\SAVScan.exe
C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Documents and Settings\Ellen Kelly\Desktop\spybot\HijackThis.exe

O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: Web assistant - {9ECB9560-04F9-4bbc-943D-298DDF1699E1} - C:\Program Files\Common Files\Symantec Shared\AdBlocking\NISShExt.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Program Files\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O3 - Toolbar: Web assistant - {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
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [IS CfgWiz] C:\Program Files\Common Files\Symantec Shared\cfgwiz.exe /GUID NIS /CMDLINE "REBOOT"
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O16 - DPF: {2BC66F54-93A8-11D3-BEB6-00105AA9B6AE} (Symantec AntiVirus scanner) - http://security.symantec.com/sscv6/SharedContent/vc/bin/AvSniff.cab
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/SharedContent/common/bin/cabsa.cab
O16 - DPF: {74D05D43-3236-11D4-BDCD-00C04F9A3B61} (HouseCall Control) - http://a840.g.akamai.net/7/840/537/2e529727a6ef04/housecall.antivirus.com/housecall/xscan53.cab
O16 - DPF: {9F1C11AA-197B-4942-BA54-47A8489BB47F} (Update Class) - http://v4.windowsupdate.microsoft.com/CAB/x86/unicode/iuctl.CAB?38145.8653472222
O16 - DPF: {CE28D5D2-60CF-4C7D-9FE8-0F47A3308078} (ActiveDataInfo Class) - https://www-secure.symantec.com/techsupp/activedata/SymAData.cab
O16 - DPF: {E77C0D62-882A-456F-AD8F-7C6C9569B8C7} (ActiveDataObj Class) - https://www-secure.symantec.com/techsupp/activedata/ActiveData.cab

any ideas, or if more info is required, feel free to ask.

Alejandro