You can edit the project file (.prel), if you still have it and all of the media files you used in it. At least you can if you still have Premiere Elements 7.
I would not recommend editing a version 7 .prel with a newer version of the program.
Until SG gets to your thread which appears to have detoured into a new one posted by you, please consider the following
Premiere Elements 7 Windows...
Set your project preset for NTSC DV Standard or NTSC DV Widescreen or PAL counterpart (whatever is applicable to the DVD-VIDEO on DVD disc that you have)
Rip the VOBs (VTS_01_1.VOB and others in the series if applicable) from the DVD
DVD (Camcordr or PC DVD Drive)
Adobe Premiere Elements - Media Downloader/Advanced Dialog
You will need to redo the menus from the original DVD.
If you need more details on the above, do not hesitate to ask.