Completely wiping and reinstalling the OS will probably do it some good.
You should also see what type of RAM that is installed in the computer. If it's an older type of ram (such as DDR or DDR2), the computer may benefit from an upgrade to a newer type of ram. DDR3 or DDR4 would probably be fine.
edit: your cpu only supports DDR3. use that
Installing a graphics card would most likely make it a slight bit faster too, when running games. The integrated graphics in the CPU may be letting the machine down.
If the computer still has a HDD (Mechanical Hard Drive), upgrading it to an SSD will certainly make it much faster. Doing this simple step of adding an SSD can save many old and slow computers, however others not as much; it's always worth a try though as it will always somewhat increase the performance on any computer.