Hi there,
It happen that I had a virus and or adware/spy ware on my PC that change the policies in the registry (TaskManager and RegEdit Access Right Disabled). Norton catch the virus and destroyed it, but the reg key was already changed. I browse the net a bit and I found that some people had the same problem. So here is how to fix this:
1) Clean the Virus
2) Since you can't access REGEDIT go on
http://www.regxplor.com/download.html, download and intall the Registry Explorer (Freeware), actually this program is better that the RegEdit
3) Start Registry Explorer
4) Go in Registry\HKEY_CURRENT_USER\Software\Microsoft\Wind ows\CurrentVersion
5) Go in Policies\System
6) Double-click (right panel) on DisableRegistryTools and change the value for 0
7) Double-click (right panel) on DisableTaskmgr and change the value for 0
Thats it. Hope that will help