Fix: Crashing on Startup [Windows 10]

• Open Windows Defender Security Center, and then select Virus & threat protection > Virus & threat protection settings > Add or remove exclusions.
  
• Under Add an exclusion, select the file option
  
• Navigate to the Crysis2.exe (Usually \steam\steamapps\common\Crysis 2 Game of the Year\bin32\Crysis2.exe)

Crysis2 should now run.

update: you must be logged in as an administrator to make these changes.