on startup do you see the option to boot to recovery console..?
should be just before windows starts to load ,if you do, select this option, let it boot .
then from the flashing cursor type in CHKDSK /F(NOTE THE SPACE BEFORE THE FORWARD SLASH).
this will check the filesystem on the h/drive and report any errors and should fix them .once finished type EXIT and then the pc should boot into windows .
if the option is not there then you will have to use the windows cd to boot to the recovery console and do the same .Dave.