bill - 12:58 am on Oct 5, 2010 (gmt 0)
As kaled suggested I'd also try
chkdsk /r first. However, once a sector is marked bad it won't be used any more, so you can continue to use the drive in most cases. I would certainly consider a new drive if possible.
Another utility I've had success with is the SpinRite product. It's not free, but my license has paid for itself many times over. I use this program for HDD maintenance and recovery.