How can I stop WUAUSERV?

make sure you are Logged in as Administrator user before you run Disk Cleanup

Sounds like you almost got it...when you delete the contents of the C:\Windows\SoftwareDistribution

then restart windows service with the following commands...

net start wuauserv

net start bits

then Windows update service... will have to rebuild the contents of C:\Windows\SoftwareDistribution... which may be a few gigabytes ... 

which will definitely take some time depending on your hardware RAM, Processor, other processes running, hard drive space (check your hard drive space.... if you are running low on space, could cause slow issues) 

My experience with windows update I've seen it take around 2 hours to rebuild C:\Windows\SoftwareDistribution contents, but I've heard others say it took longer for them

First I would try to run "Disk Cleanup".  Disk Cleanup will check your C: drive and tell you how much space you will gain....if you do run it.  

It will also automate the process of clearing/re-setting windows update...  You may have a button that says "cleanup system files..." you will have to click it.  and i think it will search your c: drive again

Disk cleanup will also clear the C:\Windows\SoftwareDistribution folder... so after you run it it will need to rebuild it... so it will take time also... so I would at least give it 2-3 hours if possible or just let it set there overnight. 

I know its totally insane to have a Windows Update progress that says "100% Completed" or "Looking for updates" and its just sitting there for hours, but I recommend giving it at least 3 hours or even better let it run overnight.

Also another thing to recognize that Disk Cleanup may take time depending on how much space it will need to delete.

Then when you reboot it may say Windows is updating and that will may also take a long time and will fill you with rage.

if they both finish, then from then on... Windows update will hopefully not take as long to check for updates 

Thank you for your responses. The problem is still not fixed. I was able to stop the service, delete the files in softwaredistribution, etc., etc. I then restarted Windows Update. After 35 minutes of watching it say "Looking for Updates" I finally gave up. WINDOWS UPDATE DOES NOT WORK. I got started on this saga because for days an update was stuck at 2%. In the process of research to fix this problem guess what I learned: A LOT of other users are having the same problem I have. I posted this problem on my FACEBOOK page and many of my friends are also having this problem - and it is clear that Microsoft is ignoring it. I halfway expect them to come out with, "Oh, no problem, this is the new standard!" 

I have now used the following process to TURN WINDOWS UPDATE OFF on my computer. I realize that doing so makes my computer vulnerable, but no more nor less vulnerable than trying to get updates through a WINDOWS UPDATE applet that does not work. 

(1) Bring up the Task Manager

(2) Click on the Services Tab

(3) Select and right click on any service

(4) Select Open Services

(5) Scroll down to find Windows Update

(6) Select and right click on Windows Update

(7) Click on Properties

(8) Select the drop-down menu next to Startup Type

(9) Select DISABLED

also you can confirm that "Windows Update Service" is stopped after you reboot

by going back into Services -->finding Windows Update --> viewing the status --> status should be "stopped"