You haven’t said what systems are multibooting, nor which one was installed first. Here are a few solutions using my crystal ball:
1. If you want to return to XP after removing Vista or Win 7 and XP was installed on its own initially, you have to reinstate boot.ini, as follows:
- Boot from the XP CD and select the first repair option (R) which will take you to the Recovery Console.
- Type fixmbr and press Enter.
- Type fixboot and press Enter.
- Restart the computer.
If asked, type Y to the continue message.
2. If you want to return to Vista after removing another version of Vista or Windows 7 and the one you want to keep is the one that was first installed:
- It is much easier than returning to XP. Download EasyBCD, scroll down click here and get the instructions click here Just go to the Add/Remove Tab.
3. If you want to keep an operating system that was installed as a second system, it’s more complicated and you will have to post here which systems you have and what partitions you have.