Verified answer

Why are you still letting him use the computer? After that threat he should have to use computers in the library.

If you're using Windows XP or a business version of Vista go to start..run, type gpedit.msc to open the policy editor. Right now I'm on a Vista Home computer which doesn't have gpedit.msc so I can't tell you the exact policy you need. Somewhere there's a Control Panel section which offers various restrictions on control panel applets.

Those policies can also be added directly to the registry. If you have Vista Home you can try adding them that way. I don't know if removing gpedit.msc includes disabling the entire policy concept, which would prevent that from working. Won't know til you've tried. A time-consuming Microsoft Support search should show you the correct registry values.

edit, another thought: Depending on Windows version, you may have the option of bumping him down to a lesser type of user. In Windows XP Professional a "User" has less rights that a "Power User" and probably wouldn't be able to uninstall anything important. Vista Home only has 2 types of users. Not sure about XP Home and Vista Business.

If your computer has home edition i dont think your can set permissions like that but when i get on mine ill take a look and let you know but you should be able to