ok plummy well what you need to do is.
Go to your internet properties or browsing history or soemthing.And delete your history and your cache.
Update Java then Restart Computer
Get some weird browser and use that instead.
If all else fails, Backup all your stuff on some CDs. Then FLush your PC which means put back to the way it was when you bought it. With only standard programs on it. Then re install everything off the disk and place it onto your computr again.
Idea 5- Ask GOOGLE!!