Driver Letter J, K, etc.. not on list for mapping ntwk

We are in a client-server environmet. When the user logs on to the domain, a batch file runs that is supposed to map the appropriate network drive letters to the shares on the network. Windows XP has no problem doing so... We installed our 1st Windows 7 workstation and are now having problems with the drive letter mapping on the 7 machine.

Heres the issue: The drive letter(s) that I need to map, for Instance K: drive, is not listed as an option when I try to manually map a drive. Also, the drive letter has NOT been used because it is clealry not mapped.

Pls. help if you can

This might help you find them.
How To: Show/Hide Drive Letters In Windows 7 & Vista

I have noticed in my machine that if I don't have a DVD in the drive the drive doesn't show up in Windows Explorer. In fact I have 2 DVD drives and neither show up. Also the drive letters are not available when mapping a drive. I'll bet you have a card reader using up those drive letters. Open computer management then disk management to have a look. You can reassign drive letters there too.

Solved. Thanks for the tips here. What is was is my monitor has some external ports that are connected through a USB cable that runs from the monitor to the CPU. Those ports took the drive letters that I needed, but I could not see them becasue an option in "Folder Options" was checked that said "Hide inactive drives". Once I unchecked that option I could see that the drive letters were actually in use. I unplugged the monitor USB cable from the CPU, rebooted the computer and the drive letters mapped correctly. I then plugged in the monitor and the monitor ports were given random drive letters that I'm OK with.
Thanks

I figured that hide drive letter option was it. Thanks for reporting back in. Solved.

Please don't forget to Rep. :)