It is essential that you at least run Linux if you're dealing with crypto. Windows is complete malware-filled trash and you just can't protect youself from it - antivirus programs are frequently not detecting them. Sorry to say, but it seems that your BTCs has been stolen.
You are right. Now I also think that was a steal. And I understand - Bitcoins not return ...
Linux ... One word - late.
In conclusion - thank you all for your participation and your time.
P.S. If anyone have an idea on how to return the stolen - will be grateful (in PM)