[Tom O'Farrell]

i have been using Reaper for several years , first just audio , then video.
things were working fine , but then one day it just crashed.
Since then i can do audio no problem, but every time i open the video window reaper refuses to respond to any commands , even just stop playing .also no video (picture). this is accompanied by a loud buzzing and i have to force stop the computer.
i'm using Windows 10, 64 , an going through an Edirol UA-4fx.

i have tried uninstalling Reaper and re-installing , to no avail.

can anybody help please?
i would be extremely grateful
Tom O'F