Hi,

There are several reasons this may occur. Let's take a look at Event
Viewer for any System Restore logs that may have been created recently
that may help us diagnosing the problem.

Go to Start - Run and type eventvwr.msc and press enter.
Click on System in the left pane.
Click the gray title "Source" at the top of the source name column in
the right pane to sort by source name, look for "sr" and "srservice".
Double click on each of these events, then click on the button below the
two arrows in the upper right corner. This will copy the event
information to the clipboard. Paste the information for each of the two
event here. There's no need to post duplicate Event ID's.

How do I use the Event Viewer to search for System Restore logs?
http://bertk.mvps.org/html/tips.html#EventViewer

Here are some more links for troubleshooting System Restore.

System Restore Failures to restore:
http://bertk.mvps.org/html/srfail.html

System Restore fails to create an automatic restore point:
http://bertk.mvps.org/html/srauto.html

i restored the cpu but the product number on the computer is not working in
restoreing the programs it just there..

You don't have any restore points for your computer to restore to. Use any
antispyware you have and scan your system, do the same with your antivirus,
use Norton's utilities to to fix any problems you might have, make sure you
have at least 12% free hard disk space of your total hard disk size,
optimize by defraging your hard disk. This is a cleaning up process of your
hard disk. Unless you have a virus or corrupt XP files this should take care
of your restore problems. Give your computer a little time to establish a
restore point, then try to restore it.