Does it say. Bad video card drivers? If so. I had this same problem. I had xP, That was teh problem. So i bought windows 7 ultimate. I could use minecraft after that. Usually if you update them its not going to help anything. Your os just needs to be above what minecraft needs. Xp is already out of the game for minecraft. Vista is ok. Windows 7 is best for playing minecraft.
I guess you need to upgrade now.
Just update your gfx drivers.
just google "insert what brand your gfx driver is here" graphics drivers.
Or just get windows 7 and not have to do that. Or i could send you a torrent i found on a cd and mail it to you.