What computer operating system is your Premiere Elements 11 running on?
Please give more details on what you mean by "I can't access it."
a. If you click on the Premiere Elements 11 desktop icon, does the program open to the Welcome Screen?
b. If it opens to the Welcome Screen, can you open the Elements Organizer or Video Editor from each of the tabs in the Welcome Screen?
c. Are you referring to opening a new project or opening an existing project that was saved/closed or do you not get that far, that is, you never see the Expert or Quick workspaces of the program?
How long was the program fine before you could not "access it"?
Is you video card driver up to date according to the web site of the manufacturer of the video card?
Do you have the latest version of QuickTime installed on the computer with Premiere Elements 11?
Is the program set up as Run As Administrator and from a User Account with Administrative Priviledges?
Is your computer optimized and cleared of pile ups of preview files, conformed audio files, and conformed video files?
The answers will be in the details.
Let us start here and then decide what next.