More information needed for someone to help... please click below and provide the requested information
-Premiere Elements FAQ http://forums.adobe.com/thread/1042180
If you are having a WINDOWS runtime problem, you might also search at Microsoft
You will need to supply a lot more information than just "runtime error in premiere elements" in order for us to help you.
1. What version of Premiere Elements are you using and on what computer operating system is it running?
2. What are you using a the project preset for your project? And, what are the properties of the source media that are being used on the Timeline?
3. Is this a "it worked before but now" or "it never worked before" type of problem?
4. What is the description of your computer and its resources?
5. What troubleshooting have you done so far...
a. flushing preferences
b. deactivation, uninstall, reinstall
The following is an Adobe document on run time error troubleshooting.
Let us start here and then decide what next based on your details.
Add On..I did not see SG's post until after I had posted mine.