Wyo....as you keep using and re-using your computer, the stuff you look at, download, delete, etc keeps being written and over-written on your drive....and eventually it is like un-sorted closet shelves..things are piled everywhere...pieces of files are in different places, so when you want something, it takes longer to get to it because the pieces have to be assembled for you...this is a 'fragmented' drive

so, there is a way to fix that...you de-'frag'ment it..with a program that is built into your operating system....exactly where this is depends on what system you are running...