several arduino uno under xp

Situation: In a pool of xp computers some students should learn arduino. The computers are mirrored from one image. Only the single board that was connected during the installation of the driver is recognized by all computers. But every student should play with his/her own board.

Is there any solution?

Yes, we have to use this xp installation. win7 comes in two years, when we get a new building. And they never won't run linux.


There must be something bad. Any Arduino connected to a computer with Windows XP must recognized and then XP will assign the first free COM port number to the Arduino.

Restricted user privileges not affects this behavior.

The problem is solved!

A registry entry disables the recognition of other arduinos as a new hardware:


Create a key IgnoreHWSerNum(vendornumber)(serialnumber) For example


Found at

Thanks to Max Manfred Piendl