That’s a lot of different problems. Have you thought of formatting your PC and reinstalling Windows from scratch? They also call this, “reformatting”, “reimaging” or “full Windows recovery”. This is what I do at work if I see that an individual computer is filled with tons of problems and will probably take too much of my time away while I fix other computers at my job. I would especially recommend this from the problem that you fixed just by pulling out the cord from your cable modem. It seems like there is some sort of additional spyware inside your PC that might steal info like passwords or other personal data. The 100% sure way to destroy this threat is to wipe out your PC and install Windows from scratch.
Before you wipe out your Windows install make sure to backup any important data you may have. Then use the Windows disc (sometimes called recovery disc) that came with your PC when you bought it to reinstall Windows.
On some PCs that disc is built into your hard drive which you can easily access. When your PC turns on you will see some sort of message on the screen that says something like, “Press F11 for System Recovery” flash on the screen for just a second. Press whatever button it tells you to press to access it.
During the recovery process it will ask you what type of Windows System Recovery you want. Look at the 2 or 3 options it has and select the one that sounds the harshest. It might say something like “destructive reinstall”, select the harshest sounding option. That will kill any type of virus, malware or spyware your PC has.