I don't think you can disable it, and if you could it wouldn't do any good as all the policy controls are set by the GPE making changes to the Registry. Those changes/restrictions would remain in place even after disabling or removing the GPE.
What you need to do is log on using the 'Administrator' account, open the GPE console and reverse any restrictions that aren't to your liking.
If the 'Administrator' account was password protected by the original owner (a strong possibility on a corporate PC) that's another issue beyond the scope of my experience. My own way of dealing with that, and taking into account all the restrictions that annoy you, would be to buy a copy of XP, wipe the existing installation off and start afresh (don't take too long deciding on this course of action though, as retail stocks of XP will become scarcer that now that suppliers are pushing Vista.
Editing the GPE restrictions is dealt with here:http://www.techimo.com/articles/index.pl?photo=61
Edited by pip22, 28 February 2007 - 09:19 AM.