This is for Windows 10 and above computers. At each restart time how long it takes for Windows to boot up to same point.

1. Get and run CCleaner – it’s free – find it via Google. Run it and delete as much as it can find. If running it on a very old computer click as many options as possible. YouTube videos show how to do it.
2. Run DiskClean-up – YouTube videos show how to use it. Use it for SystemFiles. Delete all.
3. Check for SystemRestore points and delete the lot – YouTube shows how.
4. Run chkdsk – again YouTube shows how.
5. Restart computer.
6. Run Defragmenter – it comes with Windows – this could take up to 10 hours or more on badly fragged drives.
7. After completion restart computer.
8. Only then update Windows.
9. Restart computer.
10. Disable hibernation

9. Restart computer.