Windows 10 Clean

  1. Check and install updates then shut down fully and restart computer 

  2. Run clients own virus software or Windows Defender if one is not installed

  3. Create a system restore point (search restore point)

  4. Back up important files

  5. Run Windows update

  6. Check how much memory is being used (Windows Memory Diagnostic)

  7. Empty recycle bin

  8. Run Defrag (Defrag) But not on a SSD (Defrag will show you)

  9. Disable unrequired start up programmes (Startup Apps)

  10. Check background apps and turn off unneeded ones (Background Apps)

  11. Turn off Windows tips and tricks (Notifications and actions)

  12. Check if One Drive is always syncing

  13. Turn off search indexing (Services App) Scroll down to either Indexing Service or Windows Search in the list of services. Double-click it, and from the screen that appears, click Stop. Then reboot your machine.

  14. Turn on storage sense run it and use it to delete old versions of Windows and set it to delete temp files that apps aren't using

  15. Make sure automatic page file management is turned on (View Advanced System - In system properties select advanced tab - select settings in the performance area - In performance options select the advanced tab then select Change in the virtual memory area - Make sure the Automatically manage paging file size for all drives check box is selected. If not select it and restart laptop.

  16. Uninstall any unrequired programmes

  17. Check Downloads folder

  18. Adjust the appearance and performance of Windows (Search Adjust the appearance and performance of Windows - On the Visual Effects tab, select Adjust for best performance > Apply. Restart Laptop.

  19. Run Windows trouble-shooter (Troubleshoot settings)

  20. Run Windows disk clean-up

If they have a spare USB can use Readyboost instead of adding more RAM

ReadyBoost lets you use a removable drive, like a USB flash drive, to improve your PC’s performance without opening your PC and adding more memory (RAM). To use ReadyBoost, you’ll need a USB flash drive or a memory card that has at least 500 MB free and a high data transfer rate. 

To use ReadyBoost

  1. Insert the USB flash drive into a USB port on your PC.

  2. Select File Explorer  from the taskbar.

  3. Press and hold (or right-click) the USB flash drive (or SD card if you used one instead), then select Properties.

  4. Select the ReadyBoost tab, then select Use this device.
    Windows determines if the device can use ReadyBoost. If it can’t, it'll let you know.

  5. After Windows determines how much free space to use to optimize memory, select OK to reserve this space so ReadyBoost can use it.
    When you look at the contents of the USB flash drive in File Explorer, you’ll see a file named ReadyBoost.sfcache on the flash drive. This file shows how much space is reserved for ReadyBoost.

Note: ReadyBoost can't be used if Windows is installed on a solid state drive (SSD). An SSD is already fast, and ReadyBoost won't be able to improve its performance. (To check if laptop has a SSD run Defrag and it shows you)