Windows 7 Two mirrored internal HD's got same designator letter- cannot fix

[hartstoc]

I installed Windows 7 Ultimate on a newly formatted scsi drive that carried designator "D"(the existing "C" was a smaller SCSI that I wanted to get rid of) I removed the old "C" drive and installed another new scsi(identical to the new boot drive). The second drive was recognized but did not get a letter assignment. I configured the second new drive as mirror to the other("D"). Worked fine except that the second drive was also asigned "D" in the process, and seems to be working fine and has been successfully loaded as a mirror. I want to change the designator of the first(or either one, really) to "C". When I try to do that to either one, I get the flag: "the parameter is incorrect". Can anybody help?? Motherboard is Intel S5000VSA with Xeon 2.5 GHz quad. Thanks

 

[hartstoc]

Solved! I killed the mirror, re-formatted the freed-up drive(which gave me a chance to assign the letter "C" to it), installed the OS on that, made it the boot-drive, reformatted the former boot drive("D"), and made it mirror to "C". Cool!