System Defender problems that MalwareBytes isn't fixing

I don't know how exactly I got this spyware onto my computer but nothing is getting rid of it, including MalwareBytes and Ad-Aware.  It's already causing tons of pop-ups and it's disabled my Firefox browser and won't let it load without crashing.  I tried running MalwareBytes and saw the infections but MalwareBytes said it couldn't remove them and would try to delete them once I rebooted the computer but immediately after I get a message saying MalwareBytes has stopped working.  I checked with the Best Buy Geek Squad and the only advice they can give me is to reformat the entire computer or pay $200 for them to fix it.  Is there anything at all I can do short of this?  ANY help would be greatly appreciated!  

In case no one is answering me because I didn't attach the HijackThis log to this post, it's because I downloaded that program but it kept giving me weird messages while I tried to run it on my system - something about how the write file couldn't be done or found or something like that, I don't remember exactly.  In any case, it wasn't working.  I don't know what to do.  Someone please help!