Can not create a file named nc.exe

We are performing an upgrade for a Library Database program.
The upgrade failed. One of the files delivered with the upgrade is called nc.exe.

We noticed that we can not create a new file with that name anywhere on the server.
The software needs to install a file with that name.

We get a message that a file with that name exists already. It does not. We are also trying multiple folder locations and multiple drives.

Does anyone have an idea what is going on???

Thanks for your help.
Bob