Yes the boot partition can be relocated. In fact, its preferred position is at the front (the far left visually) before any other partitions with OSs. When used as the boot partition, the 100MB "System Reserved" is marked as THE active partition on the boot
drive, so the bios has no problem finding it.
There are different ways to move partitions, the third party app Partition Wizard is very helpful. One can shrink the first partition to leave room for the 100MB "System Reserved" partition, then use "Copy Partition" to relocate it to the now empty space
at the front of the drive. Once the new "System Reserved" is marked active (make sure the old partition is no longer active) it should be possible to boot to Windows 7 again. If not, use the DVD or the "System Repair" CD and do the "Startup Repair". Once booting
is restored, return to Partition Wizard and remove the old 100MB partition and rearrange your partitions as desired.
For reference: http://technet.microsoft.com/en-us/library/dd799232%28WS.10%29.aspx
Cheers!
Robert