Locate the Setup.exe file of the Adobe product that is displaying the error. You can find it in the folder where you extracted the installer files or in your Downloads folder (if you downloaded the installer directly).
Last updated on
Nov 19, 2025
Learn how to resolve error code 21 "System requirements not met" during Adobe app installation.
Error code 21 appears when your device doesn’t meet the minimum system requirements for installing Adobe apps. It can occur if your operating system is outdated or no longer supported, your hardware doesn’t meet specifications, or Windows Compatibility Mode is enabled.
Windows Compatibility Mode is enabled
Windows Compatibility Mode (WCM) helps older programs run on newer versions of Windows by simulating an earlier Windows environment. However, Adobe installers aren't designed to work in Compatibility Mode, and using it can cause installation errors.
If Compatibility Mode is on, disable it before reinstalling the app.
Right-click Setup.exe file and select Properties.
Select the Compatibility tab.
Deselect Run this program in compatibility mode for. If this option is already deselected, reinstall the app.
Select Apply, and then choose OK. The settings are saved automatically.
Run the installer again.
Note
If disabling Compatibility Mode doesn’t resolve the issue, check your device’s system requirements and update your operating system, if needed.
