good job, you nailed it!
OK, let's go through the Speccy report and see what shows up.
an old gal indeed.
Speccy shows you have Spybot - Search and destroy as your anti-virus.
Windows 10 has an excellent built-in AV program called Defender, ranks easily as good as the paid-for guys.
so for starters, I'd recommend removing it and that will auto-enable Defender.
if this doesn't pan out, we can always reinstall Spybot later.
next, it shows your Windows Update and not set to auto-update, so click on Start, then the Settings cog, then Update & Security, then click the Check for Updates button.
then, it shows your BIOS is 5 years old.
while there may be updates, I doubt any would fix your issue you are describing, but food for thought later on if we have to start clutching straws.
your Seagate 500GB hard drive has been booted up nearly 4000 times, and is showing RAW values that should be zero, even though those catergories show as Good.
try doing the following from an elevated command prompt.
• chkdsk c: /r
• sfc /scannow
• dism /online /cleanup-image /restorehealth
• dism /online /cleanup-image /startcomponentcleanup /resetbase
I would also download Glary Disk Cleaner and run it to clean out all the built up accumulated crap.
do all that then let us know what is happening with the PC running slow, and with the movies.