Starting late last week, a small window - black inside, usually no words in it - keeps appearing for a nanosecond every few minutes, alternating with the desktop icons blinking at roughly the same intervals. One of the results of this is some slowing of computer function, especially a lot of pages "not responding" as things freeze for a few minutes. The small window goes on and off too fast to read the heading that'd identify it.
At the same time as all this, I keep getting a performance alert saying Google Chrome is using a high number of CPUs. The thing is, I did try to download GC from the Google Image page in order to possibly access a chat room I'd lost access to (a whole other issue) by augmenting my existing Internet Explorer. When I did that, I got a box saying my computer's security wouldn't let me download Google Chrome (the box did not have any Norton markings). But that was about 3 months ago, GC never loaded, and now I'm getting CPU usage alerts about it.
I checked the "details and setting" on the performance alert box, and it identified the GC thing as a file called "fjvhlqohwmx.exe". I discovered that it came from rundll32.exe when I was trying to ID the other exe file. That fjvhlqohwmx file showed in Norton Insight to have a trusted rating, and was only problematic in likelihood of crashing, which was rated "unknown". A quick glance at the window in one instance may have shown its header to be labeled as that file, but, again, too fast to know for sure.
I've tried a Quick Scan on my Comcast Norton Security Suite, to no avail. Then I tried a Full System Scan (which, due to my computer's slow performance too over 20 hours to complete!), which got at least 18 tracking cookies, but no change. The problem won't go away, even if I turn my computer off for hours, or take its battery out for a couple minutes. I really need help with this. Any idea what all this is would be of utmost help. Thanks in advance!