Windows 8 is the latest version of Microsoft's OS so I am not sure what upgrade you are expecting.
If you mean "Windows Update", the normal process of Microsoft sending us security updates and OS updates, then the 'electronic' process is a well known and much used one by now and Microsoft are quite expert at it.
There is an update available for Windows 8 to upgrade it to version 8.1, so I wonder if that is what you mean? If so, have a look at Carol's thread in the link below where this has been discussed;
Hope that helps.
I would to find anyone who has successfully used the windows 8 electronic upgrade ? to discuss their experiences