Laptop keeps freezing at random times running Windows 8?

[JStevenson]

My toshiba laptop will seem to just randomly freeze up whenever it feels like, the periods between freezes can vary anywhere from 5 minutes to 3 or 4 hours so its completely random and it does not seem to happen when I'm doing a specific task, I can be watching a video, browsing the internet or even just using the desktop and it can do it. I've run various scans but nothing has come up and I'm almost at my wits end so any help would be greatly appreciated, thanks.