For DMA mode: Control panel> System>Device Manager. Expand "IDE ATA/ATAP Controllers>Properties
>Advanced and then check each instance is set for DMA mode. If you are a bit nervous messing about in there set a Restore point before you start, call it something like "before I ****ed with the drives" !
BTW, does the motherboard have any SATA drive headers? If so you could get a 1TB SATA drive at some point and move everything over to it. These are so fast that there is no speed advantage in having projects on a second, physical drive, tho' you lose the security of splitting System and data (all eggs in one drive basket but again, you should have all work duped elsewhere anyway) When the time comes to upgrade the PC the drive can be moved into the new one...OR! Use the XP machine with huge drive as a server on a network (copper network that is,."We" don't do any of that wireless ***t for music!).
Re
the Reaper files on the second drive. Now that you have them back on C, open a project and then save it to the second drive (NOT copy and paste it) Shut everything down, reboot then go to drive 2 and find the project..."Open With"...Reaper. Just done that, works for me. If that works you can ultimately delete the files from C.
Hmm, If you only have an 80G C drive, how big are the music files? Say a gig or so for XP, Reaper, then other trash. I am thinking that you could backup a goodly proportion of your music on a 32G usb stick, 20 quid?
Dave.