Blank white screen

Does this happen with any particular web site or just by using the internet in general? Because you say it's random can you see if it's when your last web site is the same when the white screen happens ? When you say restart are you sauing restart the computer ? Does this only happen with the internet ?

I don't think it has anything to do with a particular website and i'm not even sure it has to do with the internet for sure. I know facebook has been used by my girlfriend right before it has happened on more than one occasion and yes I am unable to safely shut down and have to hit my hard restart button.

It may have something to do with your web browser , what are you using ?

Mozilla firefox exclusively.

If this issue only happens when you are browsing the internet and you are finished it goes to a white screen I would say that your browser is causing the issue.
Try uninstalling it and then reinstall with the latest release. If it still does it then try a previouse version or even try another browser like Chrome just to see if it continues to do it.