A long running thread on Microsoft’s TechNet gives details of a problem that has existed since the fall of last year. A Windows 7 machine with the default Windows Update settings checks for updates once per day. This process of checking for updates was consuming an inordinate amount of resources, upwards of 1.5 to 2GB of memory, for almost 30 minutes. Machines with only 2GB of memory were basically unusable while this was occuring. All you could do is sit and wait for it to finish or turn off Windows Update.
Finally, Microsoft as addressed the problem and released a new Windows Update Client for Windows 7. Strange, however, that it is an “optional” update. Even stranger considering that the updates that offer the free Windows 10 upgrade is “recommended”. For machines with less than 4GB of memory, this update is, in my opinion, critical.
If you’re running Windows 7, make sure you install KB3050265. Details here