If you want to save your pwad with a new name and as map01, and there is a level in ZETH.INI
already for map01, then ZETH will shut down and unceremoniously return you to Windows.
Edit ZETH.INI. Either add a # in front of 'File = map01', so that it is not read, or replace map01
in 'File = map01' with the actual name of your pwad, if known beforehand.
Save your pwad as mapxx, which is different from the one in ZETH.INI.