Provided everything is properly backed up you could reset it to factory default - this means it would be exactly as it was when you bought it so you will have to set it up again and (probably) install the latest updates. It is a faff but a reset really does make any device whizzy again - just be absolutely sure that your photos etc are backed up.
tamaris, I do it regularly with all my devices - PCs, laptops, tablets, phones, everything.
It is vital that you realise that your PC will be wiped so you must have backups. If your desktop is Windows 10 you have options - you can choose to keep your files if you want to.
https://www.laptopmag.com/uk/articles/reset-windows-10-pc