partiton lost after installing xp as dual boot on windows 7 laptop

guyz i used win7 and wanted to install xp as a multiboot on my laptop for trying an xp based encyclopedia but when i installed xp i got error "ERROR LOADING OPERATING SYSTEM" so i reinstalled xp and realized that i cant see my 2 25 gb partitions full of data,so kindly guide me to get my partitions back i have currently reinstalle win7.

Hi neelbha - Welcome to the site

There should be a repair option from Windows 7 DVD that simply restores the boot files.

And if you are looking to Dual boot - The older Operating Systems have to be installed first. You see XP doesn't know what to do with Windows 7. But Windows 7 does know what to do with XP. If you install XP even to a different drive you are changing the boot files and will no longer boot windows 7.

i need to recover my "2" lost partitions having"50 gb" data how to do that?