my laptop today has just started to suddenly go to a completely white screen with no warning and the only way to clear it is to force a reboot. Done it a few times now. Any suggestions??

Take it to a reputable repairer - a reputable company as opposed to an individual unless you personally know them. Your laptop/computer contains your life - in the wrong hands all sorts of information can be gleaned about you. I wouldn't go off recommendation from a forum either as we're all just "virtual" contributors (unless of course you really know this person) All my devices are apple and I take them either to the apple shop or the computer company down the road - costs a bit more but very secure.
Most companies also have an on line or over the phone service where they can talk you through your challenge
I'd also make sure you;re backed up in case your system crashes - but get it sorted sooner rather than later - in my experience it's a warning that something isn't right!

Hi there, One option maybe to contact these guys, who are really helpful:http://liguriapcclinic.com/ They can do all sorts over the phone and are very professional.Good luck

thanks for your help. am taking it to get looked at tomorrow and have bookmarked that site for future use

I think you done absolutely right thing.It must be gone into hang section thats why your laptop screen goes white.By rebooting the laptop this problem may be solved out.

I had it looked at, seemed ok for a few weeks and then it started again and got worse. The upshot was the motherboard was damaged so had to get a new one in the end.no idea how that happened- any idea how a motherboard gets damaged?

Possibly from overheating, make sure the vents on the bottom, sides or back dont get covered.