windows 10 running very slow

[Geoff S]

Tried running disk clean up, system error memory dump files showed 7.90 GB, checked the box and pressed, OK and delete files, the green line moved all the way, when I ran diskcleanup again the mem dump file was still there at 7.90GB.
then clicked on system files it has been on calculating, Previous Windows Installation, with the green line frozen at about 1/3.

[Midknyte]

You could delete the dump file manually. You have to show hidden files first. Open Explorer > View Tab > Check "Hidden items"
Then delete C:\Windows\MEMORY.DMP

[Geoff S]

Thanks that worked, also tried to delete windows.old by changing its attributes, but could not delete. Would like to as this is taking up a lot of disk space.

[Midknyte]

I'm assuming this was an upgrade to Win10, not a clean install. Wasn't there a "Previous Windows installation(s)" in Disk Cleanup? That should have removed the Windows.old folder.

Otherwise, try this:
https://support.microsoft.com/en-us/...ion-of-windows