Ok, here's the story. I recently installed Xubuntu on a friends PC (Due to his windows being virus infested) and it didn't autodetect his HP Deskjet 3920 printer. So I messed around with cups and it kept asking for a username and password when I tried to add the printer (I tried the local user and root, then I searched around and added a user and password via the cups command, can't remember what the command was though) So I tried installing the Gnome and KDE printing systems which failed (couldn't download dependencies).
So if anyone can help with this, I'd greatly appreciate that, and so would my friend.

Edit: It's a USB printer.

I'd say cups is the way to do it. I've had a similar problem before, and the trick was that cups was looking only for users in the "lpadmin" group (and my apologies for any haziness in my memory here, I'm reasonably sure this was the right group). When I added my username to that group, I was able to get into the cups configuration and add my printer.

I did this through the KDE menus; if you're not using KDE you could do "usermod <whoever> -g lpadmin" as root.

Using XFCE, tried the command but it says lpadmin doesn't exist, so I do "sudo adduser lpadmin" and it says user already exists.
Does anyone have an answer to this problem? It's really urgent, since my friend does a lot of printing...

Solved the issue with help from this link https://help.ubuntu.com/xubuntu/desk...iguration.html