What version of Internet Explorer are you running? If you click once on the program icon to highlight it, then look under the "File" drop-down menu at the top-left of the screen, go down to "Get Info." You can also simultaneously press the Apple "Command" key and the "I" key for "Get Info." It should provide the version of the program that you're running. Microsoft has discontinued development and support for the Mac version of Internet Explorer. The final version of IE for pre-OS X Macs was 5.1.7 and the final version of Outlook Express was 5.0.6. With pre-OS X versions of the Mac OS, you can help out programs that tend to run out of memory, by
allocating more memory to the program - provided that you have enough installed memory to set aside the specific amount to the program. The "MoviePlayer" plug-in is for QuickTime - Apple's equivalent of Windows Media Player. Internet Explorer is (by default) set with too low a memory setting, that causes freezes/crashes. It needs to have the high end or "Preferred" memory setting increased for trouble-free operation, as does QuickTime.
QuickTime's MoviePlayer shouldn't be needed to run any of the OS 9.2.x Update downloads. If the downloads were compressed file archives, having the ".sit" or ".bin" suffix, you need to download an older version of "
Stuffit Expander" (similar to WinZip) for pre-OS X Macs. You may already have it installed in a folder called "Aladdin." Use Stuffit Expander to expand the compressed files that you have downloaded.
If you wanted to obtain a universal installer disk of Mac OS 9 or 9.1 (white disk with large number 9), you might get a better understanding of the older Mac OS, from the ground up. Those discontinued installer CDs aren't inexpensive, so if you don't mind searching eBay, you could probably get a better deal. Avoid model-specific Restore CDs, because they contain a software build that's tailored to the Mac they shipped with, and may be lacking key software components needed by your 9600 or 9500.