Hi,
I sympathise with your predicament. Unfortunately though Microsoft has re-released the nagware prompt and marked it as an "Important" update. This means that if you have Automatic Updates configured, the nagware will install automatically.
To rid yourself of the problem completely, take the following steps.
What you need to do here first of all is to change the way you receive updates. With Automatic Updates enabled, the operating system will reinstall the nagware prompt which is KB3035583 after you uninstall it which will be a step we'll take in a minute.
So proceed as follows:
- Right click the Action Center icon on the taskbar and go to "Windows Update".
- In the left hand menu, click "Change settings".
- Change it from Automatic Updates to "Download updates but let me choose whether to install them".
- Click "Save Changes" and then click "Control Panel Home".
- Go to "Programs and Features" and click the link to "View installed updates".
- Copy/paste KB3035583 into the Search field top right and when it appears below, right click it and select "Uninstall".This is a large installation so uninstalling it can take several minutes.
- Reboot next and then go back to Windows Update again.
- Since you now have different WU settings, click the link if there's any which are awaiting your approval which will take you to the menu where you can decide what to install.
- If you see KB3035583 in the list, right click it and select "Hide update". The box you normally have to checkmark to select an update will turn grey and when you exit WU, those files will be sent to the repository called "Restore hidden updates".You can restore any updates which have been hidden in there at any time by clicking the link, making your selection and then selecting "Restore".
The next step is to make a registry change which will prevent Windows 10 from downloading and installing.
Hit Windows key + R to launch the Run command, type: regedit and click OK.
Navigate to: HKEY_LOCAL_MACHINE --> SOFTWARE --> Microsoft --> Windows --> CurrentVersion --> WindowsUpdate --> Auto Update --> OSUpgrade
Click the OSUpgrade key (which looks like a folder) and then in the right hand pane you should be able to see four values called respectively:
AllowOSUpgrade
KickoffDownload
KickoffSource
OSUpgradeInteractive
Some or all of these will have a value of 1. You need to change those to a 0 like you see in the screenshot.
To change a registry value, right click it and go to Modify. In the Value field at the bottom, change the figure 1 into a 0
Click OK and Windows will add the 0x00000000 (0) itself.
If it's already a 0 then you don't have to touch it.
In addition, you need to create a value. To do that, right click a blank part of the right hand pane and choose New --> DWORD with the name DisableOSUpgrade. Windows will add REG_ to the beginning of DWORD after you create it.
If you inadvertently lose the highlight when you create the new value, right click it and select Rename.
Next, right click your new value and go to Modify. Change the 0 into a 1 in the Value field. Click OK to confirm and exit.
Reboot and then go to Windows Updates. You will now be able to install 8.1 updates without being nagged by Windows 10.
If there's anything you don't understand, please don't hesitate to ask.