GWX is a Microsoft program.
Originally Posted by BunnyJ
It (supposedly) checks that the upgrade will work and flags drivers (or whatever) that might cause the upgrade to fail. There are countless examples where either the GWX program didn't flag a driver (normally the upgrade fails after first reboot in this case) or it did flag a driver but you can just ignore it anyway and upgrade.
MS aren't responsible for drivers but if they write a program (GWX) to check that another of their own programs (the upgrade) will work then they should write it better.
In actual fact not only could they have written it better, they already have. Setup.exe already includes this "what if" switch.
You can then look in setupact.log and see exactly if there will be a problem.
start /Wait SETUP.EXE /Auto Upgrade /Quiet /NoReboot /DynamicUpdate Disable /Compat ScanOnly
So the problem really is that the GWX program is rubbish and upgrades are based (or pushed) on incorrect information which MS already knows (or could know if they looked at the output of another of their own programs).
So really, if the team who wrote the program to test if upgrade would be OK could talk to the team that wrote upgrade then it would all be fine