When you first install the unit, he was recognized by Plug and Play, Windows, however, had no driver.
The driver for the converter chip requires "FTDI". After downloading the drivers from the manufacturer's site,
ran only once all good. I had caught the older driver here. Then, after the driver from
Windows Update system were refresh this, no reconfiguration of an Arduino longer possible.
After a long research on the internet I found out everything that the driver at fault.
Also an update on the latest drivers from the manufacturer did not help.
After handischen uninstall the driver, disabling the driver updates from MS
(Control Panel / System Properties / Hardware / Device settings / No .. / Never drivers ...)
and reinstall the old driver has the record again works.
If all had gone clean, there would have been 5 stars.
Because, unfortunately, a Windows adaptation of needs was to get the functionality upright, and only
the "older" drivers work there are 2 points deduction.