In older computer systems, the default type of boot drive were various spinning rpm hard drives (from 5400 to 7200 rpm), these type of drives over time get slower and slower and need to run special software to optimize/defrag them, so they are back to the full speed of the hardware. Nowadays computers are coming with newer type of boot drive called SSD (solid state drive; has no moving parts) are do not have the same issue with spinning drives becoming fragmented and slower over time. Since there are no moving parts, even with fragmentation, they do not get slower over time. They can also be up to 8 times faster that stock spinning drives and are a great upgrade for many older computer systems. If you are running the older type of spinning drive, then there are software that can help to fix the issue of your computer slowing up over time.