I had problems with Windows crashing with bluescreen errors until I connected the Cougar with the keyspan serial port adapter. Windows 7 - 64 bit system, using MTC software. No more bluescreen errors so far, but I had an issue with what I think were data transfer time-outs (I was cutting a very large file as a test; one from Paulo's svg site) resulting in a full-stop and having to close and restart both Cougar and MTC. A post on the MTC forum led me to a solution for that in the settings of the com port.
In the advanced settings I set -
RECEIVE FIFO = NONE (DEFAULT = 16)
TRANSMIT COMPLETION = FASTER (DEFAULT = STANDARD)
There were some intermediate settings, but I got time-outs with those as well in trying to cut this large file of over 37,000 coordinates). I'd guess smaller files would not require setting adjustments, but as long as everything else works as it should I will leave the advanced settings as above.
Deborah