How do I reinstall Apple Software Update in Windows?
Ah, Software Update can be reinstalled by running AppleSoftwareUpdate.msi in the Boot Camp Windows support files under Drivers Apple
(To get the Boot Camp Windows support files, boot into Mac OS and use Boot Camp Assistant to save them to e.g. a USB drive that Windows will be able to read -- see https://apple.stackexchange.com/a/247252/5231)
I had the case of faulty/old installation of Apple Software Update, s.t. it would crash upon checking for update.
I managed to fix the issue as follows,
- Get 7-zip
- Go to iTunes page, get latest iTunes for your OS
- Dissect iTunes with 7-zip, extract
AppleSoftwareUpdate.msi - Run
AppleSoftwareUpdate.msi, proceed with installation. It will automatically remove the old version and install newer files.