Found the following by Googling “Windows 7 Updates very slow”
This issue has come and gone over the years with different fixes along the way, so here is my updated guide to this issue as of this date January 5th, 2016
This is what I do when I reinstall Windows 7 with SP1 or have issues with Windows update stuck on checking for updates.
If Service Pack 1 is not installed, install it before following this guide.
Download KB-3138612 and save it where you can find it later
Download SUR Tool save it to same place
Restart the PC and disconnect from internet before Windows loads, this is important because at every boot windows will check for updates in the background and this will start the checking for updates hang all over again and will prevent the install of the downloaded packages until it finishes checking, so disconnecting from the internet before Windows loads prevents this.
Once booted install KB-3138612, if reboot is required do so and stay disconnected from internet.
Now install the SUR Tool package, this is a big package and will install many updates along with cleaning up and repairing the Windows update store. It will also cut down on how many more Windows updates will need to be installed later.
After install of SUR package reboot, connect to internet and do a manual Windows Update, it should work much faster now. Even after these fixes I have seen some W7 PC's take up to an hour to finish checking for updates if launched from Control Panel manually.
If you have other Windows updates issues and the 2 updates above are installed, download this Microsoft Windows Update fixit tool (right click “save link as”) run it and select aggressive mode to completely reset Windows updates. Reboot and try Windows Updates from the Control Panel again.