Windows Live ID sign-In Assistant is always set to “disabled”

The last two days, when I try to open up Windows Live Mail, I having been getting the error message “Windows live Mail could not be started. It may not be installed correctly. Make sure that your disk is not full or that you are not out of Memory. “  I go into Services and Windows Live ID sign-In Assistant is listed as Disabled.  Then I go into properties, change Startup Type to Automatic, click on Apply, click on Start, then click OK.  I then open up Windows Live Mail, and everything is fine.  But the next time I log onto my computer, I can't open Windows Live Mail again and the Live Id assistant in Services is listed as Disabled.  How do I keep it from being reverted back to disable all the time?  Thanks.