And you did nothing to change your computer between the last time you played it and now? You didn't move it from one location to another in your computer? Was there any hardware changes or software updates? Did you add or remove any mods?
Did you add any new software (games, apps, anything) from then to now?
It seems strange that if, say, on Monday, SS ran with no problem for you and nothing changed hardware or software wise that it would have a problem today.
I know this will sound like a cop-out, but If your current version worked but now it doesn't and you changed nothing to SS... the problem isn't going to be SS, but something in your system.