mapps, are you using a download version or a box version of P7?

If you're using download version, there's a possibility that your P7 file is actually not complete.
Windows default download feature cannot distinguish server interruption, so whenever there's a glitch on the server's end, Windows download deems it as "download completed" while actually it's not.   

There are quite a few people got the incomplete download problem and complained about it at CP forum.    A free download manager called GetRight was suggested by the CP staff as the solution, then it worked out eventually.