It sounds like you have no proof, unfortunately... I would suggest wiping your system and re-installing from scratch. Malware can do whatever it wants once it's there, and it sounds like you may be a victim. Sorry for your loss, you must be really careful with windows and bitcoin... 
This. And together with what Harkorede wrote, it looks highly likely that OP had some malware on his system which scans the screen for BTC addresses and replaces them with addresses the frauds control. you must be really careful with windows and bitcoin...
Can't stress this enough.@OP there is nothing anyone can do to help you get back your money. You maybe should file a police report, but I doubt this will help a lot. But should the malware creators one day get caught AND they still have money, chances are you might get something back. But that's a lot of ifs.
