Vista stuck in loop of running chkdsk?

I have a HP laptop w/ Vista, which I'm trying to fix for a friend. It
was initially stuck in a loop of installing an update, which I managed
to resolve.

Now, on boot, it runs checkdisk, and when it hits a certain point in
Step 2 (indexes), it hangs for a minute, and then boots to the login
screen. When rebooting, it goes through the whole check disk thing
again.

I tried logging in and scheduling it to check the disk, hopin there
was just some flag not getting reset or something, but that didn't
help. It started the full 5 stage check, hit the indexes, and started
again on the 3 stage check, and did the same thing.

I also tried running Spinrite on the disk, but didn't have any luck
with that running (after selecting the disk/partition to run on, it
just sits at the screen before it starts doing anything).

Any other ideas?

Thanks,
Martin O'B