Click start, all programmes, accessories, system tools to run disc clean up, then from system tools, run disc defragmenter.
Click start then run, type sfc /scannow
then press enter, you need the XP CD and get a blue progress bar, after the bar goes, reboot.
Click start then run, type chkdsk /f /r
then press enter, type Y to confirm for next boot, press enter then reboot.
This will take an hour, it will appear to load normally then either the monitor will show progress or the screen will go blank, do not disturb this.
When it gets to the desktop, the system files and the hard drive will be as they shouldIf no change
, the next thing to do would be a repair install, this will leave all data and settings intact, and repair XPhttp://www.geekstogo...ws_XP-t138.html
Beyond this it is likely to be a hardware fault