I have a 3 year old Toshiba laptop, not sure of the model. My problem is it takes the computer about 20 minutes to actually start after turning it on, it makes no noise, the light on the start up button does come on, but the computer itself doesn't do a thing for about 20 minutes. After it starts it will perform normal, but will freeze up after using it for a while, usually after about 45 minutes to 1.5 hours. Does anybody have a idea what could cause this?