I had an update on my system in a partially installed state. Our vulnerability scanner determined one file, MSO.dll, was still out of date. It recommended a patch to apply. Running it gave me an error message. Here’s what to do when Windows says the update is already installed on this system and refuses to let you do anything but click OK.
Because hey, from a security analyst’s point of view, this is anything but OK. I get questions about patches in a partially deployed state all the time, so I figured I’d write about it. Here’s what I do when security updates fail to apply with this error.