MrJolly,
the so called "unwarranted security features" are probably the best thing that microsoft have done for windows for ever. despite some initial problems and bugs at least with vista they have finally released a OS that has a half decent level of security built into it.
Tinkertom..
the crashing is unlikely to be cased by vista it's self, more like (as MrBounty has said) by a hardware problem, or by a badly written driver. update all your drivers to the latest versions to see if that helps.
(or install Linux, which is my preference!)