exe files open but they don't show up

[DarkOblivion]

Hey guys,
I'm having a little problem and I've been googling it (the universal solution haha) and nothing's really come up that matches my case, so I was wondering if you could help me out.
The symptoms are:
After a certain amount of time, any new programs that I open don't appear on my computer. The mouse icon turns into the waiting icon for a little while, which leads me to believe that the program did load, but nothing appears. I try ctrl-alt-del to see if the process is now running, but the task manager doesn't show up either. Sometimes I'm able to open my computer, but then it searches and never finds anything... (the little rotating flashlight icon.)
It seems like a virus... but that's weird because I just clean installed xp pro sp1 a few days ago.
Here is my HijackThis log if it might help:

Logfile of HijackThis v1.97.7
Scan saved at 10:43:01 AM, on 9/3/2005
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\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.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:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Symantec AntiVirus\DefWatch.exe
C:\Program Files\Common Files\Microsoft Shared\VS7Debug\mdm.exe
C:\Program Files\Symantec AntiVirus\Rtvscan.exe
C:\PROGRA~1\SYMANT~1\VPTray.exe
C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\PROGRA~1\MOZILL~1\FIREFOX.EXE
C:\PROGRA~1\MOZILL~2\THUNDE~1.EXE
C:\Jon\Utilities\HijackTh.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
O2 - BHO: (no name) - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {AE7CD045-E861-484f-8273-0445EE161910} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O3 - Toolbar: Adobe PDF - {47833539-D0C5-4125-9FA8-0819E2EAAC93} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O4 - HKLM\..\Run: [vptray] C:\PROGRA~1\SYMANT~1\VPTray.exe
O4 - HKLM\..\Run: [AtiPTA] atiptaxx.exe
O4 - HKLM\..\Run: [SynTPLpr] C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - Global Startup: Adobe Gamma Loader.lnk = C:\Program Files\Common Files\Adobe\Calibration\Adobe Gamma Loader.exe
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Research (HKLM)
O9 - Extra button: AIM (HKLM)
O9 - Extra button: Messenger (HKLM)
O9 - Extra 'Tools' menuitem: Windows Messenger (HKLM)
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {3253534D-9980-0010-8000-00AA00389B71} - http://download.microsoft.com/download/F/3/4/F345356C-453F-439C-8977-81149FBF0980/wms9dmo.cab
O16 - DPF: {33564D57-9980-0010-8000-00AA00389B71} - http://download.microsoft.com/download/D/0/D/D0DD87DA-994F-4334-8B55-AF2E4D98ED0C/wmv9dmo.cab
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/microsoftupdate/v6/V5Controls/en/x86/client/muweb_site.cab?1125498500442

and... that's it!