I had RobotC working recently untill today, when I tried to load it, it stalls after displaying that little bo with the logo and a robot on it.

If I have internet connection, the little status bar says Waiting for http://robotc.net/CortexLive/?id=VEXTrial...

If I don't have an internet connection, it displays "For help, press F1"

My key might be expired (I don't think it is, last week it said 15 days) but if it is I have a key to replace it with

System : W7 64-bit, I5, IE10

Are you able to open a new program/sample program through the File menu in ROBOTC? If the ROBOTC update servers are being blocked or cannot be accessed by ROBOTC, you may see an error page instead of the normal start page; this should not affect functionality at all and ROBOTC should be able to run as normal. If this is not the case, please send in a support ticket to us directly via support@robotc.net and I'll be more than happy to help debug this issue.