I'm working on a project on Premiere Elements 9. I start to edit my timeline and a message appears that says "Adobe Premiere Elements is running very low on system memory. Please save your project and proceed with caution." It then almost immediately comes up (and sometimes this message appears first) and says "A serious error has occured and Adobe Premiere Elements must shut down. We will try to save your project." The project does not get saved and the system shuts down on me. Why does this keep happening and how do I resolve?
What is your operating system? How fast is your processor and how much RAM do you have? How much free, clean, defragmented space is on your C drive?
What type of camcorder is your source footage coming from? When you started your Premiere Elements project, which settings did you select?
If you are using photos, have you ensured that they are no larger than 1000x750 pixels, per my books and the FAQs to the right of this forum?
When you see red lines above the clips on your timeline, have you pressed Enter to render your timeline? When your timeline is rendered, the red lines will turn green, the program's performance will improve and you should not get out of memory errors.
Along with the answers to Steve's questions, you might want to take a look at this ARTICLE. It starts with a general checklist of things that can help PrE work better, and then goes on many links for tuning up one's computer for video editing, including the OS. Last, there are links to some good troubleshooting articles.