I caught something or other that has been doing very annoying things to my web browsers. For a while, it would open up a new window in Firefox every now and then with three tabs. In the URL bar, it would try to open "key", "is", and some other word on the respective tabs. Later it would open up a different set of tabs as well in another new window. Eventually it started opening up Internet Explorer, which isn't my default browser.
Additionally, the Google Maps and Google Calendar interfaces weren't working for me, or if they did they ran slowly. Web pages would not reload on the first try. I could not open "Add or Remove Programs".
I ran scans with Malwarebytes and avast! to no avail. Ad-Aware wasn't working for some reason, so I downloaded the installer and ran it. At the end of the install, it asked to restart my computer and run a scan. I let it do this.
Now my computer won't start up properly in Normal or Safe Mode. In Normal Mode, it logs into my account and shows my wallpaper but nothing else. I can open the Task Manager with Ctrl + Alt + Del, but that's it. In Safe Mode, it does the same thing but with a black screen instead of my wallpaper (which is just something Safe Mode does with wallpapers, as I recall).