Welcome to Techzonez Nischint,

If you have win98 on a second partition and you have removed all valuable data from that partition you can just boot into winxp and format the win98 partition or simply delete all the files.
when you boot your computer you should see a screen asking you to choose which operating system you wish to boot to.

if you go to control panel and system devices you will need to look for the startup folder. this will allow you to remove the win98 boot from your boot menu and you will automatically stat wwinxp on next boot

I am not at a winxp machine right now so I cant walk you thru it but im sure someone here will be happy to help.

enjoy you stay!!

egghead