Some Odd Computer Behavior, Possible Malware Found

I'm not certain if I've got a malware problem or if some system file(s) are perhaps corrupted. I'm on a windows 10, 64 bit machine. The things I've noted are below - no idea if they're even all related to a single problem or if I've got several different problems going. I've got cox internet and use the free McAfee that comes with it - it's not finding any problems. I've run Malware bytes anti-malware manually, and it finds nothing. Here are the odd things that I've noticed:

**I've been having major problems with firefox 56.0.2 using massive amounts of memory ever since I let it update to this version a couple of weeks ago - as high as 3Mb, and 98% or so of my memory (4G ram). Was having memory problems with earlier version also, but not as bad. This with a number of tabs in background not loaded, and only a handful or so loaded, within a few hours of starting firefox.

**Running firefox in safe mode (firefox safe mode, not the computer in safe mode) seems to lessen the memory problem a little - still gets to about 1.6 - 1.8 Mb memory being used - BUT literally every few seconds (maybe every 10 seconds or so? I didn't really time the cycle) firefox freezes/buffers/not responding for maybe 3 or 4 seconds, then works for a few seconds, does it again, and over and over.

**Several times in the past few weeks my start button stops working entirely. Click on it, and nothing comes up. Use the "windows - D" key combination, nothing happens. The only way I can get the start button to work again is to reboot the machine. Then it works fine for a while. I don't use it very often anyhow, so I've no idea how often this is happening - but I've found it at least 3 times in the past couple of weeks.

** The "search" function in the start button isn't working at all. Put "cmd" or "command prompt" or "firefox" even in it, hit return, NOTHING happens. Reboot the machine, the search function in the start button still doesn't work.

**There are a few specific video sites (TV series & movies) where I get a lot of pop-ups/pop-unders/new windows with ads/phishing attempts etc. Even tho I've got ad block plus and the ad block pop up blocker running. I'd assumed, since it was just those sites, that it was a site issue rather than my computer - now I'm not so sure.

**a couple of times while watching videos and shifting to full screen, the task bar stays displayed rather than disappearing. That's while using VLC player. I think it happened with GOM player too, but can't swear it. Rebooting the computer makes it work properly again. I THINK this is happening only after windows liveupdate has run, downloaded updates, but they're not installed yet because I haven't rebooted the computer. I think that is why because the last time it happened, I went to task manager and saw liveupdate was still in the process of running, and when I rebooted the computer to fix the task bar display problem, it did a computer update.

Because of the weird start button problems, I tried to run the windows 10 "system file checker" in scan only mode - and got an error message saying it was unable to launch the program.

So I came here because you guys are awesome :-D, and followed the support protocol.

I ran all the other programs, but was unable to run mgtools - it launched a window, then I got a dialogue box asking if I'd allow the registry editor to run... that was unexpected but I reluctantly said "yes" only to wind up caught in a loop with it asking me if I'd allow something over and over again (I'm sorry, I don't remember exactly what it was asking, maybe if I'd let it edit the registry?) - and I couldn't see what was in the main window other than "access denied" each time, because it would immediately bring the dialogue box up again so I couldn't see anything else. I had a hard time even managing to kill it, but finally did. So I'll let you folks tell me what you want me to do.

I've attached all the other logs. I didn't attach the last malware bytes anti-malware log, since that program wasn't in your protocol, but did the malware bytes adwcleaner as required. I can add the malware bytes antimalware log (or create one) if needed, just let me know (the protocol is a little confusing on this issue).

Thanks so much in advance for your help!!