Problems with WSUS. Fails or Not Working

Today my WSUS stopped working, every time i tried to install a new update it failed.
I googled a bit and found a few guides to get it working.

I have had the best luck with Method 2.

Here is what you need to do:
Method 1:

1. Open a command prompt. (If you don’t know how please contact a technical support person)
2. net stop wuauserv
3. regsvr32 /u wuaueng.dll
4. del C:\WINDOWS\SOFTWAREDISTRIBUTION
5. del C:\WINDOWSUPDATE.log (if this tells you that it is in use just go to the next step).
6. regsvr32 wuaueng.dll
7. net start wuauserv
8. wuauclt.exe /resetauthorization /detectnow

Method 2:

1. Open a command prompt. (If you don’t know how please contact a technical support person)
2. net stop wuauserv
3. regsvr32 %windir%\system32\wups2.dll
4. net start wuauserv

Method 3:

1. Download the relevant version of Windows Update for your system
   AgentWindows, x86-baserede systemer
   http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.0.6000.381/WindowsUpdateAgent30-x86.exe
   Windows, x64-baserede systemer
   http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.0.6000.381/WindowsUpdateAgent30-x64.exe
   Windows, Itanium-baserede systemer
   http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.0.6000.381/WindowsUpdateAgent30-ia64.exe
2. From Start -> Run click Browse and browse to wher you downloaded the Windows Update installation.
3. Add the following /wuforce to the end of the path.
   C:\WindowsUpdateAgent30-x86.exe”/wuforce
4. Click OK
5. Follow the installation guide

There you go, you should be able to request Windows Updates and they will download and install as you expect.

See more here
http://support.microsoft.com/kb/943144