Solution - Windows 8.1 stuck on checking for updates:

1. Create a new local user administrator account from PC settings > Accounts > Other accounts > Add an account > Sign in without a Microsoft account (not recommended) > Local Account >
   
   
2. Choose a simple username (such as 'wuadmin') and set a password you won't forget.
   
   
3. Sign out of the current user and log into the new local admin account (wuadmin).
   
   
4. After the new account setup is complete, create a new personalization Theme, enabling a screen saver and disabling sleep, hibernation and fast start while the computer is plugged in:
   
   <Right-click on the desktop>, choose: Personalize > Screen saver > pick a screensaver and set the Wait time to 10 minutes > Change power settings > Show additional plans > High performance > Require a password on wakeup > Change settings that are currently unavailable > When I press the power button: Plugged in - Shut down > When I press the sleep button: Plugged in - Do nothing > Password protection on wakeup - Don't require a password > Shutdown settings (uncheck all of these): Turn on fast startup (recommended), Sleep, Hibernate, Lock > Save changes >Create a power plan >High Performance > Plan name: wuadmin > Next > Create > wuadmin - Change plan settings > Change advanced power settings > Change settings that are currently unavailable > Hard disk - Turn off hard disk after - Plugged in - 0 Minutes > Sleep - Allow hybrid sleep - Plugged in - Off > Display - Enable adaptive brightness - Plugged in - Off > Battery - Critical battery action - Plugged in - Do nothing > click OK, Cancel, close window. Click Ok to apply screen saver settings. Click Save theme > Theme name: wuadmin. Close Personalization.
   
   
5. Sign out of the wuadmin account, and back into original user account. Once completely booted up, do start > search for the following command: netplwiz. Click on the first result (which has a system icon for it).
   
   
6. You should see a list with both user names, your original user account and the wuadmin user account. Both should only be members of the Administrators group. If the wuadmin account shows that it is a member of Administrators group and the and Users group, select and highlight the wuadmin account, click Properties > Group Membership tab > click Other: Administrators > press OK.
   
   
7. The window should close and the wuadmin account should now only be in the Administrators group. Click OK.
   
   
8. Download and attempt to install, in the order below, the following three Microsoft Knowledgebase items: KB3172614, KB3173424 & KB3138615. (You must choose the correct 32-bit or 64-bit version that is appropriate for your version of Windows 8).
   
   https://www.catalog.update.microsoft.com/Search.aspx?q=KB3172614
   
   https://www.catalog.update.microsoft.com/Search.aspx?q=KB3173424
   
   https://www.catalog.update.microsoft.com/Search.aspx?q=KB3138615
   
   You may find that one or more of these are already installed, in which case the standalone installer will tell you so. Move on to the next one. Once you've installed the final one, (KB173424), you should restart when prompted to do so.
   
   
9. Once you've restarted, you should be able to run Windows Update normally. The first time you run it, it may take multiple minutes to load the list of needed updates. Mine took about 30 minutes via a WiFi connection. If you can use a hard-wired Ethernet connection instead, it should speed up the process for you.
   
   

HOPE THIS HELPS!