Whenever my system restarts, a black screen with white letters tells me that there is a problem detected with hard drive, and to press enter to continue.
This occured after I swapped the measly 20g harddrive for a slighty less measly-but-still-small 60g hardrive. At the time, I was running ubuntu 10.04, and during typical computer use, a warning would pop up that said for me to "back up files immedietely, disk failure is imminent!" but it was fine for months without any problems, save the error messages themselves.

Now that I am running 12.1, and occasionally a box pops up that says "System error detected", and the previously described start-up situation occurs whenever restarting. I wondered if there was anything I could do about this, because this minor annoyance started as a sort of "At least I didn't completely destroy my system" thing, but now it's a huge "first-world problem".