System plays games sometime and sometimes won't play any at all

If you are not able to play game perfectly on your system then you should have to keep your system away from virus and dangerous file that affects your system. According to me, it's better to play game on online site because there you are free from this type of issues. Recently, I also played situs poker domino online and it runs perfectly online on my system. If you also want to play this game then just have a look at http://kingpoker99.site/news.php?id=2399

Try cleaning the laser lens with a laser lens cleaner for video game systems.
or, if you have easy access to the laser lens, use a q-tip dipped in rubbing alcohol (not dripping) to clean it.
gently place the q-tip on the laser lens and gently twirl it.
use other end of q-tip to dry it, gently twirling it.
hope this helps ;p