Since my primary Windows 7 partition (C:) ran out of space, I made a disk image with Seagate Disk Wizard (which seems to be a version of Acronis True Image) and restored the image to a bigger partition (J:) on another harddisk. After that, I added with bcdedit a new bootmanager entry with the information for the Windows version on J:\ and booted into that version.
Everything fine to this point, but how do I get rid of the old C:\ partition and change J:\ back to C:\?
I tried reassigning the letter from Windows within, which quickly resulted in very weird (yet interesting) behaviour, since I hadn't any C:\ anymore. I changed it back since it obviously doesn't work this way. Now, how do I do this correctly? And what happens to the 100 MByte System Restore partition Windows automatically creates on install? Its on another disk than my primary boot partition.