If you have the student version and at startup you get an error message about an invalid license, a possible cause is that your computer is not connected to the internet. To fix, run Pro/E while you have an internet connection. There are some things you can do to configure your computer to let Pro/E run while off-line. These are described on the Pro/E web site, but it is simpler to connect.
You may also find that the student version of Pro/E randomly crashes your computer. You'll be going along just fine, and then at one mouse click, all of a sudden your computer freezes.
A possible cause is that Pro/E and your graphics card are not getting along. Pro/E is very demanding on OpenGL graphics and if things aren't just right, a hard crash occurs.
The recommended solution is to create or modify your Pro/E config.pro startup file to add "graphics win32_gdi". Here's how to do this:
Use Notepad to create a plain text file named config.pro.
Add this line: graphics win32_gdi
Save the file in the text/ subdirectory of your ProE installation. This most likely will be the folder C:\Program Files\ProENGINEER\text.
Restart Pro/E.
(If you want to see if this did anything, comment out your change in config.pro by adding "/*" to the start of the line. Then restart Pro/E and see if the crashes come back.)
External troubleshooting resources. Given the nature of the web, these links may or may not be active:
The Pro/E Student Edition FAQ from Parametric Technologies
http://www.ptc.com/products/proe/studentedFAQ1.htm