a. Type gpedit.msc in RUN dialog box and goto:
User Configuration -> Administrative Templates -> System
in right-side pane, set "Prevent access to Registry editing tools" to either Not Configured or Disabled.
b. Just type following in RUN dialog box and press
REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f
