Hi Wolfgang, Thanks a lot for your fast reply!
>To write it using the dd command was not working but I managed to write it >with win32diskimager (maybe somebody can explain this?). No error messages are thrown. After a processing time of maybe 45 Ill get this: root@tjener:/skole/tjener/home0/rm/Desktop# dd if=debian-edu-9+edu0-USB.iso of=/dev/sdb1 bs=1024 5711872+0 records in 5711872+0 records out 5848956928 bytes (5.8 GB) copied, 1794.52 s, 3.3 MB/s root@tjener:/skole/tjener/home0/rm/Desktop# Kind regards, Roman