All online modes in the PC version of Call of Duty: Modern Warfare III require TPM 2.0 and Secure Boot to be enabled. Players planning to play Multiplayer or DMZ at launch should also check their TPM firmware version. Even if the system shows both features are enabled, some PCs may still need a BIOS update if the Intel PTT or AMD fTPM versions are incompatible.
Currently listed incompatible versions include 302.1.2.X and 303.1.2.X for Intel platforms, and 3.X.0.X for AMD platforms. Players can press Win+R to open the Run dialog, enter "tpm.msc", and then check the current version under "TPM Manufacturer Information".
This issue is not limited to very old processors. Two PCs equipped with an Intel Core i5-12400KF and an AMD Ryzen 5 5800X respectively also encountered version incompatibilities, even though their BIOS had not been updated for several years.
Players who need to upgrade should visit their motherboard manufacturer's website, download the latest stable BIOS version corresponding to their specific model, and follow the update procedure specified by the motherboard. Since updates usually reset settings, players must reconfirm that Secure Boot, TPM, PTT, or fTPM are enabled after completion.
Players should also check whether settings such as memory XMP or EXPO profiles, fan curves, preferred boot drive, and Resizable BAR have changed. These requirements help secure the firmware and boot process via Secure Boot and TPM verification, assisting in protecting online modes against cheats or malware.