When i go to the Control Panel and select "Devices and Printers", a green progress bar begins to fill the address field from the left. It never reaches the end, and I don't see my devices and printers.
It may not be a print spooler, but if it was there would probably be an error message.
The Devices and Printers windows also contains other types of items. I have seen delays when the internet is being checked, so you might try removing your network connection to test, or a drive is not being read correctly, as an external or a device attached to a printer. If you have any media extenders, perhaps it is involved. Do you see drive activity or hear any noises.
I would suggest disconnect anything you can, to see if it makes a difference.
If you cannot figure out what it is, perhaps some other software might be required so you can watch when you open the dialog. Sysinternals has something called Process Monitor that can make a log of what is happening. Perhaps if you wanted, it could be used. Let us know if you want to try something like that.
In the meantime, it would not hurt to open an administrative command prompt and type the following followed by enter:
This will check your system files to see if some are missing or damaged.
You might also open Task Manager, and check the Services tab to see if "Spooler" is running.