How about starting up from your VISTA startup disk (CD/DVD/floppies), then try deleting.
(Sorry I didn't realise Birdy's link was same as mine.) * Make sure you are disconnected from the internet at that time. Even turn your modem off or disconnect your cable to such.

Well I'm young i never installed it onto the laptop, my dad did, i'm not sure whether it was already on though, it the Vista installation disk the one that says notebook or is that a program, as the box that the laptop came in says notebook on it.