Thank you for supplying information related to your Premiere Elements 11 Windows 7 64 bit issue.
Where are the source media for your project saved on the computer hard drive?
Where do you have the Scratch Disks for your project directed and how much free hard drive space is at that
Did you install your program to the default installation location on Local Disk C or did you do a custom install
to another drive?
We should wait for the answers to the above, but you may want to delete the Adobe Premiere Elements Prefs file and,
if that does not do the work, the whole 11.0 Folder in which the Adobe Premiere Elements Prefs file exists. Be sure to be
working with Folder Option Show Hidden Files, Folders, and Drives active so that you can see the complete path
Local Disk C
and in the 11.0 Folder is the Adobe Premiere Elements Prefs file that you delete. And, if that does not work, delete
the whole 11.0 Folder in which the Adobe Premiere Elements Prefs file exists.
Let us pause here, review and consider, and then we can decide what next.