This is SOMETIMES related to a Windows Update causing a DLL change which makes your graphics adapter driver version obsolete
What is your exact brand/model graphics adapter (ATI or nVidia or ???)
What is your exact graphics adapter driver version?
Have you gone to the vendor web site to check for a newer driver?
-If Windows, do NOT rely on Windows Update to have current driver information
-you need to go direct to the vendor web site and check updates for yourself
ATI Driver Autodetect http://support.amd.com/en-us/download/auto-detect-tool
nVidia Driver Downloads http://www.nvidia.com/Download/index.aspx?lang=en-us
The graphics adapter is a GeForce 9300 have upgraded it but unfortunately it does not work
1. Computer Clean Up/Optimization
Go to Documents/Adobe/Premiere Elements/7.0 and clean out the Adobe Premiere Elements Previews File Folder. Do the same for the Media Cache Folder in that location.
Go to Edit Menu/Preferences/Media and hit the Clean button in
Media Cache Database area.
Then go to Edit Menu/Preferences/Scratch Disks, determine where all the Scratch Disks are directed to and how much free space is at that location.
Let us know the results.
2. Depending on the results, we next may do
a. Deletion of Adobe Premiere Elements Pref file or the whole folder in which it exists...path in Windows 7, 8, and 8.1 64 bit...
Local Disk C
Premiere Elements 7
and in the 7.0 Folder is the Adobe Premiere Elements Pref file that you delete. Make sure that you are working with Folder Option Show Hidden Files, Folders, and Drives active so that you can see the complete path. If that does not resolve the issue, then delete the whole 7.0 Folder in which the Adobe Premiere Elements Prefs file exists.
b. if "a" does not work then....
uninstall, ccleaner (regular cleaner and registry cleaner components), and then reinstall.
3. Always make sure that you have the latest version of QuickTime installed on your computer and that you are running the program as Run As Adminstrator or from a User Account With Administrative Privileges.
We will be watching for your results.