hello, I've also just got a rikaline gps, and had exact same problem, locking up and blue screens.
The solution to my problem:
Change assigned com port.
Device manager --> ports com & lpt --> prolific USB-to Serial Comm port (commX)
Double click -- > port settings --> advanced --> and select a different com port.. anything above 4 works fine for me even tho other ports are not in use.
also download latest drivers from
http://www.rikaline-uk.co.uk/rikaline_downloads.htm
Mick.