Run the Windows 7 Upgrade Advisor.
The best way to dual boot with separate HD"s is to unplug XP HD during install of Windows 7, set target HD as first HD to boot in BIOS setup, after DVD drive. Then after install plug back in XP, boot it using one-time BIOS BOot Menu key which on HP is ESC, unless it gives another key to press on first boot screen.
This keeps the HD's independent to come and go as you please, whereas having Windows 7 configure a Dual Boot will interlock it to XP and require surgery to later remove XP.
Other tips for getting a purrfect Windows 7 install - use the ones which apply: re-install windows 7