Karl
Let us try to delete that 10.0 Folder in which the Adobe Premiere Elements Prefs file exists.
Before you do that make sure that Premiere Elements is closed. Also, right click the Taskbar, select Task Manager/Processes, and make sure you do not see any obvious Adobe Premiere Elements processes opened/listed there. If so, right click the entry, and click End Process.
However it might be time for a deactivation of Premiere Elements 10 from within an opened project, uninstall, free ccleaner run through, reinstall with antivirus and firewall(s) disabled.
What we will use for installation files for 10 will be the Premiere Elements 10 tryout files from the following web site. Once downloaded and installed, you can insert your purchased serial number into it to make the install your working copy.
http://prodesigntools.com/photoshop-elements-10-direct-download-links-pse-premiere-pre.htm l
It is critical that you read and carry out to the word that web site's "Note: Very Important Instructions" coupled with the click "here" in order to avoid getting Access Denied.
Please review and consider, and do not move forward if you have any questions. Just stop and ask so we can work out the questions you might have about the above.
Thank you.
ATR