In general drawings are the slowest things in pro/e, especially large assy drawings
Things to try:
1. Update the graphics drivers to latest. Graphics cause more issues than anything else.
2. Remove all your pro/e settings, like config.pro, config.sup, config.win, menu.def and try to open the drawing. You might have setting that is causing it
3. ask your supplier to send their config files and compare them and or try them.
4. If the parts and assy's open reasonably, it's obviously just a drawing problem. check the drawing for additional models that aren't used.