H265 on Windows 98 SE

When on the computer

Motherboard: ASUS P4P800S-X
2.80GHz Inter (R) CPU
ATI Radeon 9660 128MB
ST3802110A 80 GB drive
Drive: HL-DT-ST DVD-RAM GSA-4167B
Network Card: EN-9130TXL
Floppy drive: GN322CA
Power supply: FEEL III-400 ATX
RAM memory: 1GB

with Windows 98 SE installed and K-Lite Codec Pack 3.4.5 Full codecs I open with a player, e.g. Windows Media Player 9 or Media Player Classic, the sound is very crackling and colorful squares pop out in the image.

Movie data:
Video: H.264 / AVC 854x480 30fps [VideoHandler - MPEG4 Video (H264) (AVC (H.264), Main Profile, Level 3.1, 854x480, 30,000 fps)]
Audio: AAC 44100Hz 2.0 chn 127 kbit / s [SoundHandler - MPEG-4 Audio (eng) (AAC, 44.1 kHz, 2.0 chn, 16 bit, 127 kbit / s)]

When I open the same movie on the same computer on Windows XP Professional SP3 with the same codecs, it plays normally.

Is Windows 98 not compatible with the H265 codec or have the wrong codecs been installed?

I can't help with such an ancient version.

Use Windows XP. The latest compatible version of the pack for that is 13.8.5.