Upload does not work, no communication

IDE-Version 1.8.8
Arduino Mega2560 (original)
OS: Win7

The arduino is connected via USB, virtual serial port 22. I can read the board information from the tool menu, so communication seems to work. When i try to upload a scetch, the following error message appears:

Arduino: 1.8.8 (Windows 7), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

Der Sketch verwendet 18102 Bytes (7%) des Programmspeicherplatzes. Das Maximum sind 253952 Bytes.
Globale Variablen verwenden 491 Bytes (5%) des dynamischen Speichers, 7701 Bytes für lokale Variablen verbleiben. Das Maximum sind 8192 Bytes.
avrdude: ser_open(): can't open device "\.\COM22": Das System kann die angegebene Datei nicht finden.

avrdude: ser_drain(): read error: Das Handle ist ungültig.

avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_send(): failed to send command to serial port
avrdude: ser_recv(): read error: Das Handle ist ungültig.

So obviously the communication does not work at all. Does anyone has any hint how to solve this?

BY THE WAY: The arduino IDE and especially the board manager are nearly unusable on my HD screen. All other windows programms support the 125/150% Zoom options, but Arduino doesnt.

Regards,
Thorsten

Update: I found a note on heise.de mentioning outdated device managers. So I updated the board information in the device manager to 1.6.22 and now it works.

From my point of view this should be installed with the latest version of the GUI without user interaction.

Regards,
Thorsten