I have win 10 works perfect. The short story is whenever I have COD4 crashes it’s always related to a sound issue. I have a Steel series 7 gaming headset, over the last 2-3 years I’ve been plagued with COD4 sound issue crashes. I believe @dLUX used to have the same issues with Steel series. It turned out to be every time my headset crashed it also crashed my game. I assume my headset corrupted my sound files. The only way to fix it was to reinstall my Steel series software. This always started when I walked away from my pc and the pc went into sleep mode.
I finally Lund a post about resetting my headset by removing the ear cover and using a paper clip to reset it.
Fingers crossed everything is working fine with no crashing for 2 weeks.
Kind of off topic but I believe most COD4 crashes are related to sound