Click on the 'Tools' then delete browsing history , Get rid of all Facebook extras like games, for less than £50 you can get a 1 terrabyte external drive to dump all your photos on and back up all your important files, this will free up a lot of memory and speed up things.
Go through all your downloaded programs and see what you never use then get rid of it.
Empty the waste bin .
Photos take up a lot of memory, go through them and dump what is not really good , you have to be ruthless. make sure your windows security updates are up to date , very important to get them automaticaly daily.