How to Enable Regedit

Go to Run --> type gpedit.msc --->User Configuration ---> Administrative Templates --> system ----> double click on "" prevent access to registry editing tools ""
Either it may be 'Enabled' or 'Not Configured'...
if it is in Not Configured state just turn it to Disabled state..
If it is in enabled state turn it to Not Configured/Disable state....
Apply ... Ok