Hi all, my first post here on the forum, although I already got a lot of information here 
My problem:
I have got an Arduino Mega that I have been testing for some while now. Through my Windows Vista PC I always have been able to upload various sketches with no problems.
However, yesterday it suddenly gave a Communication error, it seemed the board wasn't recognized any more. I removed all (virtual) Com ports from the Device Manager as I read somewhere, I installed the com port drivers new, I installed the IDE new (1.6.13) and deleted the preferences.txt arduino file, however everything at no avail.
If I connect the board to a USB port on the PC now, it does show up on the Device Manager as "Arduino Mega 2560" on COM3, and if I disconnect it disappears, so the PC seems to recognize it.
However, if I start the IDE it always allows me to select ,,, EVEN IF THE BOARD IS NOT CONNECTED, and then if I try to Get Board Info, it says “Native Serial Port, can´t obtain info”.
I've tried resetting the PC a couple of times, re-installed drivers etc, but still the same.
Then I connected it to another PC (Windows 7 this time) and everything worked fine, so it's definitely not the board.
To me it seems to be some nasty Vista Com port problem, but I've been wasting too many hours already surfing for a solution, and it seems the “Native Serial Port, can´t obtain info”-problem is not very common 
I could do with the Windows 7 netbook, but I prefer to use my own Vista PC.
Anybody any idea???