For a week and a half I have had someone randomly take remote access of my MSI laptop, Its windows 7 Pro (64Bit). Once the person had taken remote access for the first time I turned of "Allow Remote Access on this computer" in the security settings, I also completed a full system scan in Malwarebytes, and then completed a full system scan with Trend Micro Internet Security. Either scan didn't pick up anything fancy. The next day the remote access hacker continued playing with me, but this only happens when I'm playing a MMO as far as I know. I have lost my Windows 7 Key in the floods, so it makes it a bit hard to do a reload.
How do you know someone is controlling your computer? Try changing the PC name. Are behind a firewall of have the PC connected directly to a modem? You probably want to buy a Router to put in between the PC and modem if you don't have one already.
I have been on at least three different networks when this has happened so I don’t think its specific to the home network. And I know that they are because when the hacker uses remote access they will open up notepad and start typing things in.
Do you have anything running in the system tray that you did not install? VNC icon maybe or something?
You better get your system off the network and do a new Windows setup on it. If whoever is controlling your system can type on your screen, he can probably capture any accounts and passwords you are using. If you used your system this way for a while already, you are probably already screwed. Unless it's just a friend messing with you.
Change your passwords for anything you use, using another PC, buy a new drive for yours, install Windows on that, do a full scan of the old drive to find anything bad on it, copy your personal files over to the new setup. I like using a new drive to install Windows on as it keeps all your files safe in case you forget something. Not really worth the 50 bucks a new drive costs to find out you forgot to save your Diablo 2 game that you spent 80 hours on.