What specific computer operating system is involved? How has Premiere Elements 11 stopped working
a. you double click the desktop icon for the program and nothing happens?
b. you get as far as Welcome Screen and nothing happens when you click Organizer or Video Editor?
Does the problem exist with the antivirus and firewall(s) disabled?
Do you have the latest version of QuickTime installed with your computer along with the program and are you running the program as administrator?
Is your video card/graphics card up to date according to the web site of the manufacturer of the card?
Are your Windows Updates up to date?
This is what I would like you to do. Download and install installation files for Premiere Elements 11 and insert your purchased serial number in these files during the installation. Does that work?
Let start with the above and then decide what next based on the details and results in your reply.
When you do the uninstall/reinstall, make sure to do a free ccleaner run through (regular and registry cleaner parts) in between the uninstall and reinstall with antivirus and firewall(s) disabled.