-- (deprecated) Microsoft Windows OS (XP/NT/Vista)
---- Vulnerability in Internet Explorer Could Allow Remote Code Execution
bill - 12:38 am on Dec 16, 2008 (gmt 0)
So having a pristine version of the program that corrupted the OS in the first place, isn't going to help you recover a safe OS configuration.
A virtual PC would have a pristine copy of everything ideally. Clean OS, clean browser install, etc. Regardless, if a virtual machine gets infected you just delete it and start another. It won't impact your machine's OS or other programs because everything runs in a virtual sandbox.