FWIW - I try regular offerings to the gods of anti-virus and anti-spyware, along with some to Windows and Firefox updates. May have only limited results, but so be it.
Then again, I have my computer grab my cursor and drag it to one corner, and not readily let go of it. Very frustrating when I need to move around in a puzzle.
I also have to deal with frequent thunderstorms that may knock out power for varying intervals, along with inexplicable power outages (not a cloud in the sky). I've had 15 to 20 minutes to get back on to complete a puzzle. When I see or hear a thunderstorm rolling in (quite often during the summer in FL), I take a break from puzzling.
May you successfully appease the computer gods.