|Do you mean you wish to have two installations of XP?|
One on the current drive and presumably in c: - and the other on your second physical drive which is letter e: ?
And then be able to boot to either - as in a dual-boot?
If so that's quite simple to do...
Boot up with the XP CD and start a "fresh/new" installation; do not opt to repair anything...
When it offers a default path/location for the new installation, change that to ensure it installs to e:\windows (or e:\winnt) - whichever... and then continue on from there.
But first... make copies (to optical-media) of all your files/data etc. from the current installation; just to be sure that is safe in event of "anything" going amiss when you install the second version. And ideally verify those copies are truly accessible on at least one other system - before proceeding any further.
Once the dual-boot is complete... both OS will have entries in the boot.ini/menu on the current Master drive; so do not lose the boot/start-up files in teh active Primary on that current Master.
If you disconnect the current Master drive and then install XP to the second drive.. you will not be able to boot the that second installation with the first drive connected... This until either you add a couple of lines to the boot.ini on the current Master drive to refer to the new version on the second drive; or you run the "bootcfg" util to add the second version to the boot.ini on the current: Master drive. And this bootcfg will be run when you boot to your current installation - not the one on the second drive!.