RichardM is right that we would benefit from some system information (see the rules about posting your DXDiag at the top of the Forum), but in the meantime, one thing this does remind me of is firewall issues. Sometimes I'd get what you're describing if my firewall hadn't been told to allow the launcher (launcher.exe) and the program (matrix.exe) through.
Let us know more information, though--I hope that is helpful to you.