My playstation freeze sometimes, what do I do?

Take a can of air and blow some air into the dvd drive. If there is any dust or specs of dirt on the laser it could cause freeze ups to happen.

Also a laser going weak after alot of use will start to freeze up as well cause it can't read the data quick enough so then you would need to get another laser for your drive but you can get them off of Ebay for fairly cheap.

Every time I play a game it freezes on me,but after like 3 minutes!This started happening after I downloaded a demo!