Okay, I recently restored my computer to its original settings. I reinstalled RTW, Alexander, and Barbarian Invasion. I go about patching them so I can play certain mods, and the RTW patch worked fine. I try to install BI patch and it won't let me and gives me the above message.
Somewhat frustrating cause I factory restored my computer partly to fix all the issues that were plaguing my computer and not letting me play, and now I can't play certain mods anyway.
Barbarian Invasion works fine, by the way. I have run it a couple times since installing it and it clearly is on my computer. I don't know what to do.