Have you un-installed it and re-installed it? Be sure to clean out your registry with C Cleaner after un-installing.
Has it full permissions through your anti virus software?
Update Windows to the latest stuff. Install the latest drivers for all your hardware, motherboard, graphics card, sound card etc.
Try un-installing some programs you don't want/need. De-frag your hard drive (unless you have an SSD, then don't bother).
These are a start.