Security :: How To Turn On Windows Defender Using Keyboard

I just got my Toshiba laptop Tuesday and I'm having a hard time turning Windows Defender on. I saw the tutorial, but I'm almost totally blind and I use the Jaws screen reader, so I can only use the keyboard and not the mouse.

I pressed the windows key, which used to bring up the search box, but now does something weird, and started typing defender, which brought up the Windows Defender app. When I pressed enter, a dialog box, or what sounded like a dialog box, popped up and said Windows Defender has been turned off, but there's no option to enable it, just a message that says to go to action center but doesn't do anything and a close button. I tried to go to Action Center, but it was really confusing. I found something that let me turn it on, but it still says it's off when I go to check it.

Not sure if the Norton the laptop came with is balking me and not letting me use Defender or what. I tried to uninstall the truckload of programs from Norton using add or remove programs, but I assume it opened Norton to do the uninstall because I heard Norton internet security dialog, but that was all it said. I'm not sure if it was uninstalling or what, as Norton doesn't work at all with Jaws. I called Toshiba because I was having a few more problems that they were able to fix, but when I asked about Defender, they transferred me to their paid tech support people who wanted to charge me an arm and a leg to do remote access, when all I wanted were instructions on how to do it myself. Is there any way to turn Defender on without having to mess with Norton or do I need to get someone to uninstall it for me?

Also, is Defender an actual antivirus program or just something to be used along with an antivirus? Security Essentials was recommended to me by an expert in adaptive technology for the blind because it was the most accessible antivirus program there was, but when I attempted to download it I found out you have to use Defender now with Win 8. What confuses me is that the Toshiba tech support worker said Defender wasn't an antivirus program. Can I use that or do I need to go the next best route and get Avast, which I hear is sort of accessible?