Computer Freezes Very Randomly With No Sort Of Prompting

Recently in the past couple of weeks my computer has been freezing at random internals with absolutely no warning or prompting at all. It's not a case of me opening a specific program, or making it perform memory-intensive tasks -it will just completely freeze up out of the blue. This morning, all I did was turn it on and by the time I came back from making my cup of tea it had frozen itself. The other day I was typing a sentence onto a word document with no other programs open and it froze. The entire laptop becomes unresponsive -the capslock key doesn't respond, although interestingly enough my graphics tablet seemed to still be responsive (the lights would change colour like normal when I use my pen on it). The only option I have is to do a hard reboot.

This has been happening intermittently for the past couple of months (perhaps starting around June?), but it's only recently starting to get worse. Before it happened once a week, and now it's starting to happen about once a day. I've run a virus check, registry clean and deleted some of my most recently installed programs but neither of them have helped.

The computer runs fine otherwise -no excessive slowing down, no crashing programs..