Taskmager is disabled by your Administartor

I have XP Professional O/S on my PC and whenevr I right click on taskbar I see that the taskmanager is greyed out and cannot click on it.
Whenever I Put the command Taskmgr.exe in Run it gives the error message "Taskmanager is disabled by your administrator".
I tried to configure it from the "gpedit" and then tried the "gpupdate /force" command from the Run but all in vain.
Tried to edit the resitry and change the taskmanager disabled dword to 00000000 but all in vain.
I have AVG security on my PC and scanned the whole computer but there were no traces for Viruses or Spyware.
Tried to search in couple of forums but was able to fix this issue.
Please guide what can be the resolution for this issue.

Are you on an administrator account? Have you made any modifications to the registry, installed anything or ran any new programs recently? If so, please list any changes or programs you have installed/run.

[Moderator]

Is this what you tried?: http://support.microsoft.com/kb/555480
or
http://support.microsoft.com/kb/555546

No I haven't made any changes to the registry but has installed M/S office full version on the PC and I have a habit of visiting Porn sites and downloading free videos.

I have already visited the following site on microsoft http://support.microsoft.com/kb/555546 but was not able to fix the issue.

[Moderator]

Okay, you said you scanned with AVG but I suggest you also download and run MalwareBytes

downloading free videos.

Bad idea. Some sites will make the videos require a special "codec" to run...and while you're clicking I  Agree and OK and submitting info, god knows what is going on in the background.

Bad idea. Some sites will make the videos require a special "codec" to run...and while you're clicking I  Agree and OK and submitting info, god knows what is going on in the background.

err .... the codec in that case would be the malware.

err .... the codec in that case would be the malware.

Video codecs can be malware? Wow...I have lots to learn.

Video codecs can be malware? Wow...I have lots to learn.

no, the "video codec" isn't really a "video codec" but a malware program.

no, the "video codec" isn't really a "video codec" but a malware program.

Ohh. Well how do they get the video to display the download/installer?

Ohh. Well how do they get the video to display the download/installer?

It's not a video.

No I haven't made any changes to the registry but has installed M/S office full version on the PC and I have a habit of visiting Porn sites and downloading free videos.

Is this what you tried?: http://support.microsoft.com/kb/555480
or
http://support.microsoft.com/kb/555546

yes I tried both the microsoft kb articles and they did not work.

your computer is clean for virus completely or not?
you'd better check your computer is completely clean.
and if you are computer is clean
than go to
start >run >gpedit.msc


go to the group policy and crack the task manager ....and it's will appear like normal


or

it does not work
you can try in dos mode (command prompt ) like this
run>cmd
and command prompt is appear
and type as follow

reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskmgr /t REG_DWORD /d 0 /f


and enter ......


you will see your command is completely successful and



your task manager service is operate normally .........



If I've need necessary ,  please consault with me by email ......

 

It's not a video.

So how do they get it to show in Windows Media Player? Make a fake one that is the exact same as my colourized version?

On a side note, I would like to point out that even though your normal AV scanner says you're clean, only an expert can really say that.