The Registry area is a very dangerous place when you don’t know what you are doing. One bad move can really mess up your system. If you are sharing your computer with your friends or family members and afraid that they might access your registry and mess up your computer pretty bad then you should consider disabling registry access. You can disable registry access by using Local Group Policy Editor (Local Group Policy Editor is not available on Windows Home editions.
Type gpedit.msc into the Search box in the Start menu.
Go to User Configuration –> Administrative Templates then select System
Under Setting, double-click on Prevent access to registry editing tools.
Select the radio button next to Enabled, click OK.
Close Group Policy Editor.
If you have a Windows 7 Home or Starter version, you can use this simple tool called Registry Enabler & Disabler to disable your registry. This utility also works on XP and Vista.