dual boot help

The question to ask would be are you dual booting across two separate drives or just seeing two primaries on one single drive?

With 7 installed on a totally separate drive after XP on the frist it's possible to remove the XP host drive and build a new BCD store and boot sector on the 7 drive to see it a stand alone drive. For removing XP from the same drive and that is on the first primary where the boot files are located you would need to use the same steps to make 7 bootable once the XP primary was wiped by reformat or deleted entirely from the drive.

If XP was installed after 7 on a second primary simply editing the BCD after the XP primary is wiped you simply removed the XP entry from the boot options and can even disable the boot options screen entirely.

Well tOnnyAyye Welcome to the Seven Forums! and the world of questions!

Across two separate drives is generally a quick fix in rebuilding the BCD store! If the XP drive is now plugged into the first sata port you would swap that to see the 7 drive become Disk #0 whenever looked at in the Disk Management tool as well as the very first drive on the system.

That will make any repairs even fresh installs if ever needed see the Windows installer place all boot files and information there ahead of any other drives installed. The rebuild coomands are typed while at the repair tools>command prompt option when booted live from the 7 dvd itself. The MS page for use of the bootrec tool as well as entering the Fixboot and Fixmbr commands to insure success with a fresh set of mbr entries is seen at How to use the Bootrec.exe tool in the Windows Recovery Environment to troubleshoot and repair startup issues in Windows

That sees results in one boot from the 7 installation disk and can be used to rewrite the boot sector information for anything including mishaps with any future dual boot where Grub ends up replacing the 7 mbr if you later decide to try out a dual boot.

The automatic startup repair often works when a drive has already seen 7 mbr information but lost in a mishap or Windows runs into any other startup problem but may several tries to see that work for a drive lacking any original entries since that would be starting off fresh. Regardless we'll get you going just the same.