click start type diskmgmt.msc and hit enter (for xp click start > click run > type diskmgmt.msc)
a box will open > right click on the "h" drive and select "properties"
click on tools tab on the top and under error checking click "check now"
click start type cmd and hit enter
type e: and hit enter
type chkdsk -r and hit enter
many hard drive vendors have software to diag and repair hard drives, if you take a look at the vendor and go to the vendor's support site you can down a piece of software if the above does not fix it.