Has it ever worked? If not do you receive an error message when installing the program? Which version of Windows are you using?
"BEX 64" stands for binary execution in 64bit mode. If it fails at that point, you have some serious problem. Either your processor is not qualified at all (doubtful, since AE runs), your operating system is not qualified or some DLL is missing/ wrong version...
Okay, I figured it out.
If I watch the splash screen, it goes through the loading of dlls and plugins. The last one shown before the crash is QuickLooks.aex. It wasn't clear whether that meant it crashed DURING it, or crashed just after it (on the next in line, or maybe whatever process is next, if that's the last), but I do recall I got QuickLooks as part of the Magic Bullet suite for After Effects (and it installs to Premiere too) and since it's not part of the regular Premiere distribution, I got suspicious.
So, I disabled the plugin (by renaming the extension), et voila! Premiere loads.
I can live with that solution. And a possible diagnostic consideration to remember - it might be the plugins. Watch the splash screen for whatever plugin loaded last, particularly if it's third-party, and try yanking that from the process.
I believe Premiere also has an option to start without loading plugins, but nobody mentioned that. That would be another obvious step.
Great job Tabjulius on solving your difficulties. I have moved this discussion to the Premiere Pro CS5 & CS5.5 forums. This will allow other users of the Magic Bullet suite to access this thread easily.
What do you do if Premiere will not start and the update will not install?