Keep getting msg that defender is off

I cannot open Windows Defender on two computers one is Home Premium 32bit and the other is Ultimate 32bit. On the Home Premium computer a msg pops up reminding that Defender is off and offering to turn it on. On the Ultimate computer when I click on Defender in the CP I get the same msg. On both computers it will not turn on or open so I can disable it. Both computers are running MSE and Anti-Malare.
How can I get them to open Defender so I can disable Defender.

Solved. I just piddled around and found that I could DISABLE Windows Defender by going to Properties in Services. Right click on Properties and select DISABLE option and then APPLY....GO.

Yep, that's the way to do it!

"NOT SOLVED"
Yesterday, I went into my account on the computer that had this problem and there staring me in the face was the msg in question. "Windows Defender is off. Click here to........". This in spite of having disabled it in services.

What could be causing this?

Hi there ... Read the Link below might be of some help

How do I remove Windows Defender disabled notification at Windows 7 - Microsoft Community

Read the link and did as suggested. Could NOT find Windows Defender in services. The services were unsorted. how can I sort them?

Bill