RE: Dell Inspiron 5000 series extremely slow
"start up from complete shut off takes up to 4 minutes 17 seconds, with active anti virus that was pre-installed, and 3 minutes 21 seconds when temporarily deactivating antivirus '
That's a very, very long time. If McAfee is the anti virus on the system, I would suggest you completely get rid of it and go with windows 10 anti virus - Windows Defender).
I would also suggest you download / run the free version Malwarebytes - Official Site to go along with windows defender. It's the best for getting rid of nasty malwares that slow down your computer.
Download / run the free version of CCleaner - Official Site. The tool will clean up all the junk on the system that could be slowing up the computer. You can even use Startup in CCleaner to disable the programs in your startup. It much better than windows task manager startup.