Thank You Michel for your reply. But it is not working. Running start "MapDrive" /wait "C:\Install\MapDrive.cmd DEU %SystemDrive%\Temp >%SystemDrive%\Temp" it says it can't find C:\Install\MapDrive.cmd DEU %SystemDrive%\Temp >%SystemDrive%\Temp By the way the syntax should be start "MapDrive" /wait "C:..." Doing it this way: start "MapDrive" /wait "C:\Install\MapDrive.cmd" DEU %SystemDrive%\Temp >%SystemDrive%\Temp It finds mapdrive.cmd but I get this message: "C:\install\MapDrive.cmd" called with the following parameters: [DEU] [C:\Temp] [] [] Der Verzeichnisname ist ungültig. The German text says that the directory name is not valid. Maybe it is because I haven't a directory C:\Temp? Mapdrive starts working, but doesn't close its window and after its finished there is a second CD Drive in the explorer, which is not there in real. Can you explain to me, why mapdrive is called diffrently from Runoncex and and from a batch or CMDLINES.TXT and what the two parameters (%SystemDrive%\Temp >%SystemDrive%\Temp) are for? I'm not good enough in batch programming to find out, by reading your batch. After experimenting a bit I found this: CALL C:\install\MapDrive.cmd DEU >%SystemDrive%\MapDrive.log 2>&1 and it is working for me perfektly. using CALL C:\Install\MapDrive.cmd DEU %SystemDrive%\Temp >%SystemDrive%\Temp I got the same error with the invalid directory name as above. The problem with the second not existing CD-Drive was my mistake. I forgot, that a new version of one of my programs installs a virtual cd drive. Thank you very much Michel @ Yzöwl: While writing this I haven't seen your post. But in the end I did it the way you indicated. Though the double-quotes didn't seem to be the problem, as I have also tryed it without quotes. I starts running but doesn't go back to my original batch. Many thanks to both of you.