backup everything you can, while you can.
then format and reinstal everything.
can you look at your last updates, and uninstal that last one and let it reinstal?
but, yes, in my own experience I've spent too long at times trying to 'fix' problems and just find it easier to wipe and start over. I do have all my software at hand though so I wouldn't lose any programs...
My laptop has been on vista for 12 months now and I've not once had any 'major' problems. Aside from once or twice my computer doesn't start up, but, I think this might be some hardware issue. As it gets half way then turns off.. and I turn it on again and it starts up and is fine..