Hi samiulla and welcome to GeekPolice!
With all due respect, I would get a new computer. 256 MB RAM doesn´t cut it anymore these days. Even for WINXP it is very few.
If you insist on installing WINXP on this old machine, you have to be a bit more specific about where the installation fails. Does it boot from the CD? Do you get the installation menu? Where do things go wrong?