Odd occasion? It happened every time I tried to install a program, delete a file, change the name of a file, open certain folders, change things in the control panel etc. etc. Nowhere was safe from it's annoying intervention! So yeah, the registry mod just disables all that crap so you have some kind of control over your computer without Windows assuming you're a complete retard.
I'm pretty sure you can't in Vista... you can in W7 but in Vista (at least the version I have which may be the issue) I couldn't do anything so downloaded the fix.