As the title says,

I already heve the 4th usb to serial adapter.
All 3 before have died.
I used different adapter (Prolific and FTDI chipset), but all died.

I use an Acer Aspire One and a Voltcraft powersupply, connected to the cigaret lighter.

Besides this the MS runs without any spikes or glitches.
Wher can I start searching to get this problem solved, I dont want to buy a new adapter every time I go for a ride.

 

The most likely issue is your laptop power supply. It probably has a ground offset which means the USB adapter sees (a lot?) more than 5V when it gets grounded by the MS. You need one that will actually have the same ground as the car or you need to power your laptop with a battery.

Jean

 

i read your title wrong and realized it a second later i thought it said (MS serial killer abducted)

 

Ok,
So I will try a second power supply,
if this also fails I will try this USB serial adapter.

http://www.elv.de/output/controller....ereich=&marke=

I think this would also work, if this is the failure.