Computer all of a sudden is super slow?

I need help my computer had never been this slow until today I haven't downloaded anything and all games i play frames are down like 60 fps and unplayable i recently set my computer to factory defualts and played minecraft and got 100+ fps now its at 40 fps on low settings and its unplayable someone please help?

You need to enable your GPU or download the GPU up to date drivers. I believe all of your video processing is being done by your CPU/APU. I recommend finding out the components you have in your computer, and downloading/updating the correct drivers.

You need to check for virus attack also.