You probably couldn't reproduce it because you had some background windows opened. If you start AIDA64 using a desktop shortcut and there are no other opened windows at all, it will always crash. But if you have any other window opened (even the Calculator), then AIDA64 starts without an issue.
Windows 9x is weird... and always was)
And yes, it crashes on a vanilla Windows 98SE
I was testing AIDA64 4.00 version