mysterious drive appears

So about 6 months ago, i was working on one of our desktops here with no user. Was at my desk, with a command window open ( with admin privileges) and running commands on her pc. i do not have the commands i was trying now, but was using psexec to run it remotely "on" her pc, and was trying to mount a share i think. it acted like it locked up and i closed the cmd window. then later, a z: drive appeared ( after my domain account logged into her pc), z: being the test letter i was using. it points back to c:\users\appdata\... . it cannot be disconnected like a network share. it acts like a real hard drive, but is not. we ddo not use roaming profiles, the only thing that would be, is a redirected "my documents" folder. non of the normal dos based commands work, they either assume network share or real drive. and it is not on every pc in out network yet. i went through and wiped out and reloaded that pc, and after i looged back in with my domain profile, the z: appeared some time later. it is a "phantom" drive junking things up, and i do not even know where to start. since im not sure what it even is, not sure what to look up in google. Please help.

it definitely has something to do with "subst"
strange mapped drive - Spiceworks

if anyone sees this in the future it was the new uniprint.
UniPrint Communities - Forum • View topic - Uniprint 4.xx - Automatic local drive creation
Add the following “String Value” in registry
HKEY_CURRENT_USER\Software\UniPrint\DriveMapping (set to "0")

Thanks! I was baffled by this mysterious new Z drive!

Here's the solution for Uniprint 5 (the solutions for 4 don't work):

UniPrint Communities - Forum • View topic - Uniprint CLient 5.0 Stopping Virtual drives