I have the PS4 version so I can only try and remember what I did, and then you can try and see if there's a PC equivalent.
I went onto the Internet and logged into RE.net. There was a button to press in the top left corner where you chose a Resident Evil game and the platform you play it on, I think. On mine I have Revelations 2 PS4 in the corner, so for PC it's probably Revelations 2 Windows.
Hopefully you can figure that part out. After that then asked me to link my PSN ID to my Capcom account. I followed the steps to log into PSN and then my account linked. Then I went onto Revelations 2 game, pressed options, tested the connection and it worked.
So for me, I had to actually go to RE.net to get the accounts to link. I don't know if there's a similar thing for PC, and maybe someone else can shed some light on that. But I thought it was worth a shot telling you how I did it and seeing if you can figure out a similar way. Good luck!