If you want us to help you, you'll definitely need to provide more information.
Which version of the program are you using? What operating sytem are you using? Have you ensured you have the latest version of Quicktime, per the program's requirements?
What model of camcorder is your video coming from and what resolution is it? Did you use Premiere Elements' Add Media tools to get the video from the camcorder to your computer?
How fast is your processor? How much RAM do you have? How much free, clean, defragmented space is on your C or main hard drive?
These questions below may be for a different product... but the information you need to supply is the same, for the products you use
More information needed for someone to help... please click these links and provide the requested information
-Information FAQ http://forums.adobe.com/message/4200840
-Effective questions http://forums.adobe.com/thread/416679
-How to get help quickly http://forums.adobe.com/thread/419406