System Reserved should be on the main disk, right alongside the Windows installation. If you're not certain, click on the Windows Start Button, type
diskmgmt and press "Enter". It'll open the Disk Manager and you'll see which disk the SR is physically on.
As for the System Reserved partition, I usually leave that alone and do not push my luck. However, in the event that the letter change option is NOT available in Disk Manager (greyed out), it should be possible to do it with
DISKPART console commands.
That said, before tinkering with anything related to System partitions and whatnot, I suggest you do a full backup of your hard drive using backup & restore software, just to be safe, as I don't know whether it's going to break something on your rig or will pass by completely unnoticed.