Completely different software... and I think P6 is also older than PE3... I doubt you will be able to open a PE3 project in P6
You will either have to create a new project in P6, or figure out why PE3 crashed
Most of this (below) is for Premiere Pro... but many of the questions are common to all problems... plus a link at the end about PE crashing
More information needed for someone to help http://forums.adobe.com/thread/416679
Some specific information that is needed...
Brand/Model Computer (or Brand/Model Motherboard if self-built)
How much system memory you have installed, such as 2Gig or ???
Operating System version, such as Win7 64bit Pro... or whatevevr
-including your security settings, such as are YOU the Administrator
-and have you tried to RIGHT click the program Icon and then select
-the Run as Administrator option (for Windows, not sure about Mac)
Your Firewall settings and brand of anti-virus are you running
Brand/Model graphics card, sush as ATI "xxxx" or nVidia "xxxx"
-or the brand/model graphics chip if on the motherboard
-and the exact driver version for the above graphics card/chip
-and how much video memory you have on your graphics card
Brand/Model sound card, or sound "chip" name on Motherboard
-and the exact driver version for the above sound card/chip
Size(s) and configuration of your hard drive(s)... example below
-and how much FREE space is available on each drive (in Windows
-you RIGHT click the drive letter while using Windows Explorer
-and then select the Properties option to see used/free space)
Windows Indexing is BAD http://forums.adobe.com/thread/676303
While in Properties, be sure you have drive indexing set OFF
-for the drive, and for all directories, to improve performance
Some/Much of the above are available by going to the Windows
Control Panel and then the Hardware option (Win7 option name)
OR Control Panel--System--Hardware Tab--Device Manager for WinXP
Plus Video-Specific Information http://forums.adobe.com/thread/459220?tstart=0
And, finally, the EXACT type and size of file that is causing you problems
-for pictures, that includes the camera used and the pixel dimensions
Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037?tstart=0
What is a CODEC... a Primer http://forums.adobe.com/thread/546811?tstart=0
What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037?tstart=0
Report back with the codec details of your file, use the programs below
For PC http://www.headbands.com/gspot/ or http://mediainfo.sourceforge.net/en
For Mac http://mediainfo.massanti.com/
Once you know exactly what it is you are editing, report back with that information... and your project setting, and if there is a red line above the video in the timeline, which indicates a mismatch between video and project
Read Bill Hunt on editing a VOB/MPG file http://forums.adobe.com/thread/464549?tstart=0
Edit Vob http://premierepro.wikia.com/wiki/FAQ:How_do_I_import_VOB_files_/_edit_a_DVD%3F
Read Hunt on Using MOD/TOD files http://forums.adobe.com/thread/699990?tstart=0
Work through all of the steps (ideas) listed at http://forums.adobe.com/thread/459220?tstart=0
If your problem isn't fixed after you follow all of the steps, report back with ALL OF THE DETAILS asked for in the FINALLY section at the troubleshooting link
Also read file troubleshooting http://kb2.adobe.com/cps/407/kb407928.html
Premiere Elements Hang/Crash http://forums.adobe.com/thread/792580?tstart=0
Reset Preferences = Press/HOLD Ctrl+Alt+Shift while starting program
Read Bill Hunt on BSOD http://forums.adobe.com/thread/772169?tstart=0
Also, you should NEVER open a project created in an older version of the program in a newer version of Premiere Elements. (Or an older version, of course.)
It nearly always leads to problems.
Always finish your project in the same version it was created it.
Welcome to the forum.
I assume that you mean either PrE 4, or PrE 7, as Premiere Elements skipped versions 5 & 6, to catch up with Photoshop Elements' version numbers.
As Steve mentions, the ability to edit a Project in a newer version of PrE is often frought with problems. Different versions offer different Effects, Transitions and other aspects that can negatively affect the capability to move up a version, or two. PrE 4 was a fairly large departure from PrE 3, and then PrE 7 was a jump up from PrE 4. PrE 8 and 9, are a tad closer together.
Still, and depending on what is in the Project, many have had luck going from an older version, to a newer version (the reverse is almost always totally impossible). However, any success is always based on exactly what one did in that older version, a bit of luck, and often errors or problems along the way.
For your specific situation, when youi Open the PrE 3 PREL (Project file), in your newer version, what sort of error messages, or problems do you get? There might be some specific "cure" for those, though maybe not.
Also, can you tell us a bit about the PrE 3 Project, as there might be a fix for the crashing in the school computer.
It could be a case of making a change to the Project in PrE 3, to allow it to work in the later version, but one cannot bet on this. Considering that we are into Summer, I worry that the school computer and PrE 3 might not be available to your daughter.
The more details that you can possibly give us, the more likely that someone can give you tips on migrating the Project, though there are zero guarantees, as it just might not be possible.