If you could please provide more details. It goes a long way in diagnosing the problem in a timely matter. It appears you're having problems with running EasyBCD in XP. You've got .net installed but the hidden reserved system boot partition Windows 7 has created may not have been detected. Here's what you can try to get EasyBCD working:
Right click on My Computer > Manage > Disk Management and assign the small partition a drive letter if it doesn't have one and set it as "Active" if it is not. Now re-run EasyBCD > Manage Bootloader -> Re-install Windows Vista/7 Bootloader -> Write MBR
Use EasyBCD in Windows 7 by getting Windows 7 to boot again following these instructions using your Windows 7 disc.
Which ever method that works once you have EasyBCD up and running go to Add/Remove Entries and add a new XP entry, allowing EasyBCD to autoconfigure XP's boot files.