Based on community reporting (Steam, Reddit, Activision support forums) and debugging traces:
The most common cause of fatal errors is a corrupted download. If you are playing on Steam, this is the first step you should take. fatal error 0xc00025 black ops 2
Older games may struggle with modern Windows features like "fullscreen optimizations". Based on community reporting (Steam
: Windows 11 22H2, RTX 3060, 32 GB RAM Symptom : Fatal error 0xc00025 immediately after pressing Play in Steam. Root cause : Discord overlay injecting discord_desktop_core.dll into the 32-bit game process, causing a page fault at sector 0 of a memory-mapped file. Solution : Disabled Discord in-game overlay globally. Error resolved permanently. fatal error 0xc00025 black ops 2