Missing drive letter

I just built a new computer which I am trying to set up identical to two of my present ones. The first terabyte hard drive is divided into 5 partitions, C thru G. Windows 7 is on C and Windows XP is on D. The other three partitions are categorized storage. I also added two more terabyte drives which are supposed to be H & I. Since my CD/DVD rom had assumed "H" in Windows 7, I reassigned the drive letter "J" to it. When I installed what was supposed to be my "H" drive, it showed up as "I". When I attempted to reassign the drive letter "H" to it, "H" is not on the list of available drives, So I tried renaming it to "Q" and then back to see if "H" would show up. It didn't. I went ahead and put the final drive in It was supposed to be "I" drive and indeed it came up correctly as "I" drive. So everything is in order now except for my "H" drive which still remains as "Q" until I can figure out how to make the "H" drive letter become available again. This si important to me since I do regular synchronization between my other computers and the drive letters need to be matched on all of them.
I am not on the new computer right now, but on my last built one which has the same setup. I didn't seem to have any problem on this one since the drive letters are all on order.
I've never had a lick of trouble getting them right on the XP partitions.
What do I need to do to get "H" back on the list of available drive letters?

Look in Disk Mgmt to see what is holding H and release it by renaming to next available letter.

If this fails, cross check with free Partition Wizard bootable CD which is more authoritative than even Disk Mgmt for these purposes. It also has a utility to rename Drive Letter once you find H.

gregrocker said:

Look in Disk Mgmt to see what is holding H and release it by renaming to next available letter.

If this fails, cross check with free Partition Wizard bootable CD which is more authoritative than even Disk Mgmt for these purposes. It also has a utility to rename Drive Letter once you find H.

Nothing is listed in disk management under H. When I first installed Windows with only the one disk drive in, the DVD rom was listed as H. I then assigned J to it. That worked fine, but it did not free H as an available drive letter. Your Partition Wizard bootable CD looks interesting, but since the drives are showing up correctly in XP I'm kind of afraid to change anything at that level.