there is a problem with this windows installer package ... can't install
Every time I try to update windows, I get a "There is a problem with this windows installer package" error. I then spend the next 45 minutes trying to download, install, run as administrator etc, before finally scouring the internet to find the procedure to uninstall the old itunes (all apple apps have to be uninstalled in a particular order), and then finding and downloading the microsoft uninstaller tool (because apple software update refuses to uninstall), before finally going back to the apple installer and reinstalling the whole thing.
This is getting tedious. Is there any way that I can avoid this 45 minute circus? Recently apple's been updating about every two weeks, and it's getting on my nerves.
iMac (27-inch, Late 2013), OS X El Capitan (10.11)