My $.02
If you have enough HD space or multiple drives, I'd have no less than three partitions.
And have the OS's make it dual boot.
XP first then Win 7
Set both up with the essentials for your needs. All your hardware drivers, Joystick software, trackir and all your profiles, ect.
Then ghost them both.
Then in a separate partition start putting in your Games and such.
This way you have two access to your machine, if one OS goes bad.
Plus if it does your ghost disc can bring it back up to speed in less than 30 minutes, per OS.
If partitions are on same drive and drive dies, its all for not, short ghosting the info to a new drive.
So having multiple drives is actually the safest.
Some guru's advise against it, but that's the TOAD way.
I went to doing it once right after I was to compete and had a OS failure, and was not able to participate.
I've never been left out since, due to HD's or OS problems.
Just Motherboards have bit me in the Arse.