Network drive letter not available

Alright, here is the situation. This crappy piece of software will only communicate if the network of drive it is talking to is k:, because of a networking error this drive was disconnected and after the problem was fixed it didn't return. I cannot map a new network drive to the k: drive because says it is already in use. I tried net use k: /delete but I haven't been able to reclaim the k: drive. Any commands or suggestions would be great. Thanks.

 

What happens when you right-click 'My Network Places' and select 'Disconnect Network Drive'?

Is the K: drive perhaps being added as a login script?

What happened when you issued 'net use k: /delete'?