http://nxway.blogspot.ca/2007/10/prt-extension-and-multiple-nx-versions.html
To open prt files with NX 7.5:
Change HKEY_CLASSES_ROOT\UGpartfile\shell\open\command to
"C:\Program Files\UGS\NX 7.5\UGII\ugs_router.exe" -version=V25.5 -ug -use_file_dir "%1"
.PRT extension and multiple NX versions
原文：http://www.cnblogs.com/amonw/p/4047166.html