At some point in 2015 computers running Windows 7 or Windows Vista started having an issue with a very long updates check. It is probably affecting Windows 8/8.1 as well. Freshly installed Windows 7 machine can spend many hours or even days to complete a check, when it was just a few minutes normally. Machines with less resources wouldn’t be able to complete a check even when doing this non-stop for days. CPU usage would stay abnormally high during the check.
I have finally found a fix for this and already tried it both at work on hundreds of PCs and on my brothers older PC, which couldn’t check for updates at all.
First, you need to go to Services (services.msc) and stop the Windows Update service.
Then install this update – Windows6.1-KB3172605-x86 (or Windows6.1-KB3172605-x64). If this update is not installing, install this one first – Windows6.1-KB3020369-x86 (ar Windows6.1-KB3020369-x64). Then reboot your PC and run the check for updates. It should now take just a few minutes.
You can download these updates here:
https://support.microsoft.com/en-us/kb/3172605 (update rollup 2016 July)
https://support.microsoft.com/en-us/kb/3020369 (servicing update 2015 April)