I'd run the game client, but it said there was a virus on the program, so I closed it. Then I re-ran the setup program and, after the installation, ran the game client again. It loaded, but then shut down on me. After I uninstalled STO from the "Add/Remove Programs" list, I reinstalled it and it says "unable to register with games explorer".
I have no idea what's wrong.

Can anyone help, please?
Comments
I'm running a full scan of the computer now; once it finishes, I'm going to re-install STO using the "Setup" program.
EDIT: I ran a full scan of my computer with AVG and nothing came up, but, when I re-installed STO, a virus warning came up, but I hit "Trust".
Still don't know why it did that...I never had that happen before.
Good to hear!
It sounds like you had an update from AVG gave you a false positive, and that reinstalling the game allowed you to tell AVG that the STO is legit.
Yeah, I'm happy everything's working again...just in time for the Q Double Rewards Weekend! hehe
Star Trek Online is a Windows only program, so if you have a Linux or Mac-based PC, the official forums aren't the best place to find the help you need. You might want to Google your issue.
That said, if you happen to have a copy of Windows lying around, there is always the dual boot option...
You may find help here: http://forums.startrekonline.com/showthread.php?t=76799