Task Manager & regedit disabled

Well, somehow Task Manager and registry editor got disabled and I can't get it working. Even with gpedit.msc I open it once, than I can't open another. Same with registry editor. Please help me out.
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Logfile of HijackThis v1.99.1
Scan saved at 9:03:50 AM, on 9/20/2008
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:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\System32\nvsvc32.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\RUNDLL32.EXE
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\laxtp.exe
C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\winpirvo.exe
C:\WINDOWS\system32\mmc.exe
C:\Program Files\HijackThis\HijackThis.exe

O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\System32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\System32\NvMcTray.dll,NvTaskbarInit
O7 - HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System, DisableRegedit=1
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
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\System32\nvsvc32.exe