If you disconnect the card reader then those letters would become available automatically you would not have to reallocate. I had a look at that partition manager thingy and don't really understand what it telling you/me. I would have used Windows disk manager or merged the partitions prior to me starting the Windows install. At that point if you just delete all the partiions you do not want they will merge into one partiton called "C" providing you have no other drives connected.