Home machine problem

[dimsum]

All,

Don't really know what or where to start, so i guess i will start here!

I am picking up someone else's computer problem.
Is a cel 950 512ram 20G HD home made machine with XP (less then a year old)
problem is, is when it boots it goes to the checkdisk screen and stop at 0%, acutally it just sit there.
can't boot into safemode, just reboot itself

I try putting the HD to another machine (back up data) and it works.
But can't do scan disk, some files right issues (so i didn't border with it)

I once got into safe mode, ran virus update, and did a scan, check out with out problem

So, I tried to reinstall XP with a reformat
It goes into that window format blue screen with the bar in the middle, but it took 6 hours to format only 36% So i am just leaving it on for a little bit more to see what is up.

as you can see i am thinking of HD problem, but what else could be wrong?

Suggestions please

Thanks!!

 

[Cerb]

Try another HD. Could also be RAM.
ANy old HD will work, though smaller is better (for format times).
Very similar issue here w/ a brand new WD 800JB...machine runs fine w/ a 6.4GB WD in it, if a bit slow.