I'm sorry. For whatever reason, I did not see your original post.
Again I'm sorry but I don't know what the SSDP, Http service is or how to check it but I am sure you are on the right track. Some of the printers are greyed out. Could you please explain.
Right click on the 'This PC' icon, on the desktop, and select 'Manage'.
Now select 'Services and Applications' and then 'services':
Scroll down the list of services, until you see 'SSDP', and check that it's running.
While you're here, check that the 'UPnP' service is running too.
If either are stopped, and you can't start them, it's probably the http service not running, which is a bit trickier to diagnose.
See how far you get, and report back.
PS: tried to add images, but failed.
Thanks for the information. Both SSDP and UpnP were shown as running but I clicked Restart for SSDP and when I checked Devices and Printers The HP OfficeJet which had been greyed was sharp and clear and then the HP LaserJet Color , which had been missing, appeared also bright and clear although it did say "driver unavailable". I tried to print to the OfficeJet; it still would not print. I think there is one other Service problem - Print Spooler. This is stopped. When I look at Properties and and then click Start it seems to be doing this but then gives an error message "Wrong Parameters". I had not put in any parameters. Do you know how to start it ?
Go to C -> Windows -> System32 -> Spool -> Printers and delete all files inside this folder. Then try re-starting the print spooler.
If it still wont start, try starting it from a command prompt with 'net start spooler'; this may give you more information about what's wrong.
Printers folder is empty. Net start spooler gives "System Error 5" "Access is denied"
I'm sorry but what is an 'admin' command window ?