Window 95 98 question

1.) Why is it when you shut windows 95 or 98 down (through shutdown) does it freeze on the windows 95 or 98 screen that says shut down. Have had it happen intermittently on both versions of windows on 3 separate computers? And what can I do fix?
2.) Where can I go to see what different verions of windows 95/98 they have out there?
Is there a site? (I know what version I have and where to find it on my pc.)But I want to see what other versions of windows there is.

Thanks