Off topic for this blog, somewhat, but the following might come in handy.
Problem: Very slow startup, computer not responding to keyboard commands except erratically and very slowly, cursor jerking and jumping or freezing up altogether.
Preliminary: Keyboard and mouse batteries (wireless) tested, replacements for keyboard and mouse tried out — keyboard and mouse problems eliminated as cause since these checks made no difference. Check-disk command run, some applications uninstalled. Checked for malware. No attempted fix at this stage worked.
Nuclear option: I did a reformat of the hard drive, followed by a new installation of Windows 10 — not an “upgrade” from Windows 7 but a new, fresh installation. Hard drive had never been reformatted before. That worked for awhile, thought that was it. Definitely needed doing. A bit of work, and a bit of a radical technical fix, but I did it. Requires getting into those tools that flash at startup. Everything loads much faster now. Note: I always buy physical important software, instead of keys and downloads. I’ve had problems trying to re-install Microsoft software from product key numbers. This time, I bought a USB drive with Windows 10 on it, off the shelf at Best Buy. Cost a bit, but, hey, I’d not bought a Microsoft software product since Windows 7, so prorated out over the years, it wasn’t that much.
Shade tree mechanic fix: Powered down, disconnected all cables including power cord, removed cover. Vacuumed all over. Fabricated a micro-vacuum nozzle out of paper towel roll core, packing tape and 1/4″ tubing, but you can buy kits with these attachments. Found lots of dust particularly in vicinity of cooling fans and heat sinks. Vacuumed thin layers of dust coating electronic components — so pervasive that I wonder if the dust shorted some of them. Then, disconnected numerous electrical connectors, vacuumed, and reattached firmly. Pulled the RAM and re-seated firmly. (Had already done that much earlier but, repeated since poorly connected RAM is reported as a frequent cause of my computer’s spastic keyboard and mouse input symptoms.)
Result: Fixed. No need to junk my 6-year old HP and replace. But, I’m replacing the HD as preventive maintenance. Like radiators and radiator hoses, they don’t last forever.