[thispc]

You don't have buy a new laptop neither switch to SSD.
Simple back everything up to a cloud drive or to an external hard disk.
Then make a clean install of Windows.
Download and install the latest drivers.

That's all. If you'd like to go further then I advise to buy a bottle of compressed air. Disassemble your notebook,  and blow away the dust.

If would like to go even more further, then remove the CPU and the GPU heat sink. Buy a thermal paste and repaste them.

Your notebook will be same good as when you bought it.

my windows  is fresh with updated drivers..though there may be dust issues..compressed air bottle should make that right..
thank you.