Welcome to the forum,
Will it launch, but no start a New Project, or will it not launch at all?
First a few quick questions, but probably a few more in a bit:
I have Premiere Elements 11 on Windows 7 64 bit as well as Windows 8 64 bit and no problems in either case.
The answers will be in the details that you offer to define your situation. Answers to Hunt's questions are critical to establishing the troubleshooting path which he and others will use to get you moving forward in your project.
Probably the only questions that I would add at this time
a. Are you running Premiere Elements 11 from a User Account with Administrative Priviledges or have your right clicked the desktop icon for the program and selected Run As Administrator?
b. Are you working from a tryout or purchased copy?
Lots of possibities once you define "...won't run...".