FSX doesn't move past splash screen.

Alright so heres the deal I recently reinstalled the Aerilfoundry CF/A-18 package into FSX and it booted once fine, but after restarting, FSX now doesn't start. It brings the splash screen up but then does nothing. For addons I only have FEX GEX, CS 757 Flight 1 PC-12, IRIS T-6 and then the CF/A-18 package, so nothing too major. Its boggling me because bringing up my task manager shows that one core is at 100% use while the other is doing nothing, usually they remain very balanced when running FSX.
My thought is reinstall, but what do you chaps think?
Cheers
Cameron
My thought is reinstall, but what do you chaps think?
Cheers
Cameron