This may be of assistance with the Client MCF problem...

I dual boot with Windows 7 64 bit and Windows Vista 32 bit. Until a little while ago, I consistently got "Client MCF has stopped working" on Windows 7 but not on Vista. I started using Vista only for Crossfire and it worked great until now. The ONLY change since an hour ago and now is that I installed Google Chrome. I think it messed with my settings and thusly interferes with Crossfire. Now I get the same error that I get on Windows 7, which I have had Chrome on for a long time now. I hope this helps. Now I'm off to uninstall Chrome!