Several of my clients with low-end OEM PC's have had this happen. HP seems to have the worst problems with their cheap-drive-failure thing...but Dell and EMachines are a close second.
Go for an RMA replacement, or replace the drive yourself. I recommend using their warranty service only for those in the most cash-strapped situations, since you'll only get another copy of that made-by-the-lowest-bidder CD drive.
That is, of course, the reason that 2400's and their ilk don't cost more.
If you can afford it, and if anyone at your place would be angry about the failure of that hard drive (and resultant loss of data), I strongly suggest you replace that one with a Seagate or Maxtor HDD of larger capacity, then copying the old files over to the new drive.