Error 126 is a Windows error that means “The specified module could not be found.”.
During Installation:
Error 126 can occur when the Windows API calls cannot add the printer driver to the system because one or more of the driver files that should be already installed are not present on the system.
The install calls Windows API functions to install the driver components and the Windows API functions return error 126.
If you are using your own custom installation, make sure that you are copying all of the files to the correct locations specified in the documentation before adding the driver. One common mistake is installing files to the SysWOW64 folder instead of the System32 folder on 64-bit systems.
Check that you do not have any anti-virus applications blocking the installation of the files.
After Installation:
If you receive error 126 after the Printer Driver has been installed, some of the driver files have been deleted from the system. Please reinstall the Printer Driver.
One common problem that may cause error 126 is reinstalling the printer driver and not restarting the system when the uninstaller asks for it.
During uninstallation, the system may keep some of the driver files locked. When you uninstall the printer driver, the uninstaller attempts to unlock the files. If the uninstaller is not able to remove the files, it will prompt to reboot the system. The uninstaller will mark the files to be deleted after reboot.
It could be that the system was not rebooted, the driver was installed, then the system was rebooted and some files got deleted. It is important to reboot the system each time the setup asks for it.
Please check that the anti-virus application did not delete any printer driver files.