For the sake of some other person or persons who may have a similar problem...
I recently had a crash with Max5 on Windows 7 that resulted in a Bluescreen and IRQL error. Nothing exceptional preceded this: I was simply opening a patch that I've opened a million times. This was after a Java update, however, I suspect this is merely coincidence.
I tried to start Max, and it simply did nothing. Looking at the Task Manager, I would see Max.exe as a process, and it would show about 25% cpu use, then gradually decline, until Max.exe was no longer a process. No error message or anything, Max just wouldn't start.
After uninstalling, re-installing, messing around with Pace extensions, rolling back Java, I eventually made my way to my user folder:
and moved the Max5 Preferences folder to the trash.
Max5 then started up.
It is worth noting that you will need to enable visibility of hidden files and folders if you want to mouse your way to the AppData folder.
I hope this saves someone the mild burning sensation that I experienced on my forehead as I tried to find a reasonable solution to this!