Windows unable to check for updates - says service not started (even though the service is started)

I've seen a few Windows 7 machines that have Windows Update problems where the machine says the service is not started even the service is started.  When this happens, the computer can no longer check for updates and it'll go indefinitely without checking for updates. The fix is to wipe out the update cache and then check for updates again.

The process as described here:

Stop the Windows Update process
Delete the content from c:\windows\softwaredistribution
Start the Windows Update process

Check for Updates.

I also recommend that you make sure the system is set to install updates for all Microsoft products as well.  To do that, open Internet Explorer and put microsoft.com in the Compatibility View sites.  Then go to http://update.microsoft.com/microsoftupdate in IE.