Hi Friend
for solve this problem you must Chang serial that enter whiling installed game
you can use this amazing page about Command & conquer Generals
https://sabio.ir/2019/10/22/install-generals-zero-hour-tutorial/
@616319841984 You are referring to a shady page in a foreign language that links to illegal downloads and unverified cracks. I wouldn't follow those instructions. Please follow the instructions here: https://answers.ea.com/t5/C-C-The-Ultimate-Collection/CnC-Zero-Hour-Serial-Key-not-valid/m-p/2074#M29 If those instructions do not help, I would advice you to do a complete reinstall of Generals and run the installer as Administrator (if you are using the CD-version.) A reinstall fixed it for me in the past when those instructions did not help.
