Preparing to reinstall XP in an XP/VIsta dualboot.

I use Vista BCD to boot XP in partition 1, Vista in part 2. So, the boot directory is in partition 1.

I need to reinstall XP, which also means I'll wipe out first partition.

Now, using using Vista CD I can try to restore the MBR and to recreate the boot folder. But a last time around it didn't work that well. So, is it a good idea to back up MBR and boot directory? And, even if I did, is it easier to re-install BCD?

Note: I can use linux CD to back up MBR.

You will need to make Vista the active system drive. That should also make it the boot drive. That way when you go to use the Vista DVD to recover the boot it will work as expected. After that you can format the XP drive and still get into Vista. Then just take the appropiate steps after XP is installed to get the dual boot back.

I, like you have the Vista bootloader in the XP partition, (active even when Vista is booted) except my Vista is the first partition ( C:\) and XP is the second ( D:\).
Vista DVD was quite happy to restore the bootloader (XP installed after Vista), but you do need to run it twice. (There is a warning somewhere in the process that the repair might need to be run more than once).
You only need to use EasyBCD to tidy up the labelling etc, not to restore function.
How did the boot repair not work well ? did it not work ? (in which case you probably need the second try) or are you saying it worked but did something incorrectly ?