you can also use the built-in clean utility
just type in search :
cleanmgr
there will be a button on the bottom for lauching it as admin. click on that to get more cleaning options.
calculations will take a while, sometimes 15mins+
after that you will have more options for cleaning. especially old windows update files.
it will take a long times. make sure sleep is disabled and power brick pluged if it's a laptop.
it's the safest cleaning tool.
after this, you can run a defrag.
normaly, if windows was isntalled on the hard drive, defrag runs automaticaly once a week already. if it does, the defrag will be fast.
but be warned that win10 is optimized for running on a ssd. it's sluggish on a hdd.
a crucial mx500 250gb is a perfect OS...