Changing Drive Letters - Four Partitions

I have two HDs; on the first one (80 GBs), I have four partitions, with XP on C: (and this is the boot drive), then D:, E:, and finally Vista on F:. I have another HD, a 1 TB one, which I use for storage, and I have made a lot of partitions on it, generally about 100 GB each. When I ran the setup for 7, I selected a partition on the second drive which was labelled S:. After 7 installed, and I opened My Computer, I saw that everything was messed up, and 7 was now on C:.

I know it doesn't mean it is physically on C:, it is still on the same partition of the second HD where I installed it, but it shows its partition as C:. I used Computer Management to change most of the drive letters so that they appear as they do in XP, but every time I try to change the drive letter of 7 from C: to S:, it gives an error, something about not allowed to change drive letter of system disk which has the pagefile.

So is it at all possible to force change the drive letters so that 7 is shown on S: and XP on C:. I opened C: (the 7 installation) and found many text files in system folders and program files which point to locations on C:, so if I force a change from C: to S:, what happens to all of these - do they automatically change their paths to S:, or does the whole thing just go phut!

I had the same problem when I installed Vista, but I didn't use it all that much, and so I didn't do anything about it, but I like 7, and unlike Vista which everyone said was an intermediate product until the next version came out, 7 is here to stay. I am ready to do another clean install if there is any way around this problem.