I've been putting off upgrading from XP because of all the hassle it'll be.... but I need to do it.
 
I had an idea today that I want to test out with you.
 
Right now I have two HDDs in the tower.  Instead of backing up then wiping out the C drive to do a clean upgrade, I'm thinking maybe I could:
1) Disconnect the two HDDs
2) Install a new HDD or SDD and load Windows 7 64-bit onto that.
3) Reconnect the two HDDs but make sure to set up the boot order to choose the Windows 7 drive first.
Then if I ever wanted to reboot in XP I could.  (And yes, I'm assuming none of the programs installed on the XP drive would operate when W7 is loaded.  But I am assuming everything on my second HDD drive (that I use for media) would still be accessible under W7.)
 
Does that makes sense?  Or am I setting myself up for a world of hurt at some point here?
 
Thanks in advance.

That's an absolutely smooth way to transition...
(You can always get back to where you were by booting into XP)

Thanks Jim.  I really appreciate your advice; it carries a lot of weight.
 
Meanwhile, I clicked on your website and let out an audible "oooooo".  When I've eked out the last of this build (that I did), I'll be starting at StudioCat instead of DIY.