If Windows starts to slow down and the system is using a SSD then check TRIM is running.
Short explanation: TRIM is a command which allows the flash chips to delete data stored on them.
Long version: TRIM clears the chips and it’s run periodically by the OS. If a chip is not empty then a SSD must read the chip, add more files to it and then overwrite the memory of the chip. The fuller the chip, the longer it takes to read, add and write back. TRIM is a command which clears out chips of files that have been deleted and therefore reducing the amount of data is held on the SSD memory and speeding up writes.
Run the following command in command line (Start > Run and type cmd and press OK button.)
fsutil behavior query DisableDeleteNotify if it returns 0 then it is enabled. If it says 1 then it has been disabled (double negative / negative logic).
fsutil behavior set DisableDeleteNotify 0