I wouldn't even move the drives. I fail to see what would be gained by changing the drives...the boot screen will present both operating systems when the system is first turned on...and either one can be designated as the default by editing the boot.ini file (if that's desireable).
Win 2K is on the first drive, as it should be...and the boot files are on that disk.
You say that you want to install XP on this second drive...and what about the current contents of that drive...what do you intend to do about those?
What is the mechanism you intend to use to install XP...a MS XP CD, recovery CDs, exactly what, please?
Bottom line: If you attempt to install XP on a hard drive which already has data on it, you may run into problems (depending on your version of XP). And you may delete files which you deem valuable, unless those files are moved elsewhere.
Edited by hamluis, 19 November 2008 - 08:49 AM.