Dual boot problems

[Qhj12]

Ok, on my computer, I have 2 partitions, one has xp home sp2, the other Has windows 7 build 7229 (which is a leaked build)
Recently, my xp activation expired because I was too lazy to find a good product key lol
But anyways, My problem is that if I reinstall XP, something in the boot manager will overwrite something making my 7 boot gone
I could easily solve this by reinstalling 7, but I don't have the time to get everything set up again (around 3 hours)
Is there anyway that this can be avoided? a custom boot manager??
Thanks in advance

[Elixer]

Are you putting XP on the correct partition?
If yes, then I think the only way to do it is take the time to reinstall.

[Qhj12]

I have 2 partitions by default both have around 70gb (It came this way)
C: Came with XP home preinstalled, but I decided to reinstall it because of all the blotware they added
and what do you mean by that?
E: I installed Windows 7

[Lightning]

back up your MBR, don't change the partition layout while installing XP, restore the backed-up MBR when you're done.

[Qhj12]

Will I have to do anything different if I install XP Pro?
I plan to swipe my stepdads cause it's official instead of my torrented one and what is the MBR?
If you could explain a little bit more I should get the rest out of trial and error.
Sorry for sounding so n00bish, I'm still learning

[Char]

you can use the 7 disk and go to the recovery console
fixmbr and fixboot should do the trick

[RetroXYZ]

You could just back up bootmgr and the Boot folder on the XP drive, reinstall XP, then copy those two files back over to the drive. Afterwards, run bootsect /nt60 C: (C: should be whatever XP's drive ends up to be) from the Win7 disc and it should work.

This post has been edited by RetroXYZ on Sep 19 2009, 07:02 AM

[Qhj12]

Thanks guys I'll try all this out and tell you whether it worked or not, but first I gotta make a disk of the build I'm using

[Lightning]

the MBR is the first 512 bytes of the disk, it contains the partition table and part of the boot loader.

I know to back it up in unix, you'd do dd if=/dev/sda of=mbr.bin bs=512 count=1 to save it as mbr.bin (on some removable media) and dd if=mbr.bin of=/dev/sda to restore it. dunno how to do that on windows.