Laptop Not Booting Up Properly! Please Help.?

ive got a Advent Laptop and ive had it for around a year or so now, one day when i went to boot it up, the boot up screen came up but it just froze, so i turned it off and tryed again, and ever since then the laptop hasn't worked, sometimes the boot up screen doesn't even come up, i can hear the fan working, but the light to wirelessly enable it. doesn't come up. what do you think could be the problem? is there some sort of boot up disk i can use to fix it ?