Drive letters after dual boot install

I recently installed Vista on my laptop along with XP. Within XP my local hard drive (partition) letter is "C" and my Vista partition has the letter "V" . With in Vista my main partition has the drive letter "C" and my XP partition is "D". How can I make each partition drive letter the same for both OS.

 

If you have other programs installed on the XP partition, reassigning drive letters can make those programs difficult to access.
Vista always wants the C; partition, wherever it sits.
Basically, the easiest way is to reinstall both xp, and Vista, with Vista being the first one you put on, then XP, then drive letters will be correct.
If you have any external hard drives, be sure to connect after installing both systems, so as to keep drive letters in order.
I use HyperOs, and have both, but I renamed any extra partitions so that I know which contains what programs - I have copies in a backup on the C drive, and, at present six partitions over two hard drives, and by keeping the correct order, I can use the second hatd drive to boot from (disconnecting the first hard drive) - so giving me a G partition to boot from on the second hard drive - its easy to live with.
You can use
VistaBootPro, but I have not used it - look up the archives at majorgeeks, as several have used/tried that way.
http://www.majorgeeks.com/VistaBootPRO_d5625.html