Thank you so much to both of you, both posts have helped me resolve this issue. It has led me to the admin page where I was able to see that these VM's were part of a 'desktop pool'
Once I lowered the number to 1 I could then power down the machines. It looks like whoever used to administer these machines put them into maintenance mode as one of you had suggested.
I'm very grateful for both of you as this issue had me tearing my hair out!!!
