When I started the upgrade, it say I have to load a SDK for Windows 8.1.
I currently have installed Windows 10, so I dont see why that would be relevant.
Probably a lot of users by now have windows 10.
Do you know why its telling me this ?
Is there a way around this ?
The SDK for Windows 8.1 has nothing to do with which version of Windows you are running - it's just the SDK version. This is required when the Visual Studio Shell is installed. I'd not expect to see an error about this on a simple update unless you didn't have any supported VS installed on the system.
If you are using version 16, the 2010 shell is ok, but won't be for the current 17.0 release. The product installs the VS2013 shell, which is why you get the message about the Windows SDK. I have seen some times in the past when the install wouldn't recognize the existing 2010 Shell.
My advice to you would be to go to the link I posted above, install the Windows SDK for Windows 8.1, and try again. It will install the VS2013 Shell and should also add integration to VS2010 Shell. Then you'll be all set for the 17.0 version (which came out earlier this year.)