Verify that the problem exists with and without the antivirus and firewall(s) disabled.
Use a mouse and not a pen and tablet device.
Assure that you are working from a User Account with Administrative Privileges.
Assure that you have the latest version of QuickTime installed on your computer along with Premiere Elements 8.
Assure that you are working from the 8.0.1 Update of 8.
If you have not, download and install the 8.0.1 Update with the program closed.
One more time
Uninstall the program the usual Control Panel route.
Do a free ccleaner run through to get rid of leftovers from incomplete uninstalls reinstalls.
Reinstall with antivirus and firewall(s) disabled.
Later, we can also invoke deletion of the Adobe Premiere Elements Prefs file and, if necessary, deletion of the whole 8.0 Folder in which the Adobe Premiere Elements Prefs file exists.
Local Disk C
It is essential that you are working with Folder Option Show Hidden Files, Folders, and Drives enabled so that you can see the complete path cited.
Please review and consider. Any questions or need clarification on any of the above, please ask.