Windows Update not working on Windows 2012 R2 Standard

Solution 1:

Two of my three 2012R2 machines exhibited this behavior last April. They would hang at Checking for updates... forever.

I never learned exactly what caused the problem, but I did get it resolved by doing the following:

Stop the Windows Update service.
```
net stop wuauserv
```
Delete the Windows Update cache directory C:\Windows\SoftwareDistribution.
```
Remove-Item -Recurse -Force C:\Windows\SoftwareDistribution
```
Restart the computer. (On one machine it required several restarts to actually get everything deleted from this directory, so keep trying if necessary.)
Run Windows Update manually again. It will fail almost instantly and offer to run a diagnostic tool. Download the tool and allow it to run.
The tool will find and fix some problems. At this point, run Windows Update manually again. Windows Update worked fine at this point.

i found this great answer here and it worked beautifully for me. Just want to share in case someone is searching:

Try this at an elevated command-prompt:

netsh winhttp import proxy source=ie

and reboot

another solution which worked for me as well was to set update mode to "Never check for updates"