Many of the older Windows 9x OS struggle playing multimedia files, as Windows Media Player 6.4 and Windows Media Player 9 are now very outdated and lack the appropriate codecs for video playback.
VLC Media Player has codecs built right in and will play pretty much any file on many older operating systems and hardware.
For best decoding results, I highly recommend at least a Pentium II processor with at least 64MB RAM.
To play AVI / MP3/ M Peg 4 Part 2/ H 264 and other files under Windows 95, Windows 98, and Windows ME:
Step 1. Download and install Windows Sockets 2.0 for Windows: Availability of Windows Sockets 2.0 for Windows 95 Direct Download: WS2SETUP.EXE
Step 2. Reboot.
Step 3. Download Platform Software Development Kit Redistributable: Microsoft Layer for Unicode on Windows 95, 98, and Me Systems, 1.1.3790.0 Direct Download: UNICOWS.EXE When prompted, extract the files to C:\Windows\System.