Today I deployed Win7 using MDT on a VM and forgot that it automatically enables updates.

after using it for a while I realized cpu usage went to 100% and ram went 3,49/3,50 which is very unusual. And it was a clean install too, no kind of virus could've infected it.

But then I saw that svchost.exe was using the memory and TrustedInstaller.exe was using all the cpu (this is a process windows update uses).

 

Then I fired up my cmd, typed in "sc delete wuauserv" and rebooted, and just like that, problem solved (that command deletes the update service). I remember same resource usage back when I was getting an updated vista install to try extended kernel.

 

If you have the same problem with Win7 simply disable the windows update service when you're not updating (you don't have to delete it)

With Windows 7 you can elect to receive notification of updates but choose when to install them yourself. I think that's a better solution.

You still have to watch for telemetry gathering tools being sneaked onto your system which can cause the sort of high CPU/memory usage described. The "Trusted Modules Installer" running once, usually just at first reboot after the updates, often pushes the system use very high for several minutes too.

High system usage problems can also be caused by some form of corruption and using a command prompt to stop the update service then restarting it may be a fix. Its little more than another turning it off then on again solution but apparently it does work in some cases.   

This has been a fairly well known problem for some time now. Try turning off Windows Update, installing the prerequisite fixers, then turn Windows Update back on. It should no longer hang on "checking for updates" consuming resources.