alternate Operating system

ok…. here it is….. I have a 8.4 gig primary harddrive and a 60 gig slave drive. On my primary harddrive I have win 98 se installed, but on the second harddrive i want to install win xp as a secondary Operating system or either installing win 98se on the second harddrive too. the reason being is that I am not going to keep the second harddrive in my computer. I am putting it back in a friends computer as his primary harddrive. so tell me … can it be done ? if so How?