Recently i have been experiencing a strange issue it appears after a hour(ish) of game time the game will freeze my screen will turn off then it will turn on again and everything will be ok but eventually it will happen a second time at which point my pc will be stuck on a black screen forcing me to shut down my pc. I think it may be a corrupt save but i want other peoples opinions encase it's something more serious.

Turn off the Autosave features and see if that makes a difference. If no joy, then start a new character or load an older one that was playing fine and see if that one has the same issues after an hour. If the new or older save does not have this problem, then your save maybe messed up. Otherwise, it could be a mod issue.

Alright i'll mess about with a few things and see if i can fix it.

Doesn't sound like your save but possibly a driver issue. Could you post a full dxdiag in a spoiler tag?

I would but it was the save i reloaded a older one and there was no problems at all.