If you manage to run CHKDSK /r successfully, then when Windows is up and running make sure you copy all your data files etc to CD. You could use Files and Setttings Transfer Wizard.
You may find that your drive will fail again in the next few days which will indicate that your hard disk is failing.
Be prepared to go out and buy a new hard disk, do it sooner rather than later and you may just save a lot of time and heartache.
Maxtor drives come with a well written and easy to follow user guide plus a great Utility CD which is bootable, it also allows you to set up a string of events such as:
Partition new disk
Format new disk
Copy original C-=Drive to new disk
This then performs each step, finishing in 20-30 minutes [about half the time of a full Xp install].
After its done, you can remove your Old C Drive and put the new drive in its place.
Rebbot your computer with a new Bigger C-drive whith a working Windows System.