Hi good evening,

I am unable to open regedit, task manager and run command not found in start menu.

Please help me in this regard. Thanking you.

That is because regedit is not a exe file (open it by search) files and folders. Make sure you know what you are doing because any changes made in regedit if they are wrong will make your computer very unhappy.

Try this---it requires using the regedit (Registry editor)

Run dialog box is missing - Tech Support Guy Forums

Don't forget to disable system restore before you attempt, it appears you're having a virus attack ! Those three components are well known to be attacked by Brontok virus,

This is normally caused by viruses.

Open Command Prompt and past the following in there...
REG ADD HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f

Still in CMD, type REGEDIT. It should open now. If it doesn't then the virus is still on your PC.
Update your antiVirus and do a full system scan.

If Regedit opens, then goto:
HKCU\Software\Microsoft\Windows\CurrentVersion\Pol icies\Explorer and \System

Delete all those restrictions, (diableRegistryTools)(DisableTaskMgr)(NoRun)(noFol derOptions)

Ctrl+Alt+Delete, End the "Explorer.exe" process and select File Run, type: Explorer.exe
Now the Run should work.

Cheers