vista problem (wait, what, a vista problem? no way! :))

so this is the fifth time this has happened. the first time was about 2 months ago, my desktop icons would be out of place and my background would be changed, and a bubble would pop up saying "your user profile was not loaded correctly." a reboot would take care of this for a while, until one time when the computer basically reverted back to factory settings (but with some programs that i had loaded onto it still left) all my documents were hidden, etc.

i took it back to best buy, paid 130 bucks to have it fixed, with what the geek squad called a root fix. (even after arguing i was specifically told the warranty i purchased covered everything, even software problems, but that's another story)

fast forward a week after this, and the same problem happened. took it back to best buy, they ran another scan, and couldn't find anything wrong with it, and sent me on my merry way.

fast forward about 2 more weeks, same problem, and they did that root fix thing again (free of charge, 30 day warranty from the first one)

fast forward another 2 weeks, same problem, and i had them completely reboot the computer, (all my files were backed up) and that fixed it up until today. same problem is starting to happen again

does anyone know the cause of this problem? where should i go from here? i'm leaning towards going back to best buy and asking them to completely replace the computer, since i'm thinking there is something going on with it beyond seemingly everyone's control.