What computer operating system is your Premiere Elements 7 running on?
Please evaluate the program with and without the antivirus disabled. If that does not help, then...
I would suggest an uninstall via the usual Control Panel route, run through with ccleaner (regular and registry parts), reinstall with anti-virus and firewalls disabled.
Do you have installation files or installation disc as well as a purchased serial number for Premiere Elements 7 or did it come as a pre-install?
We will be watching for your follow up in the morning.