The printer server ask for administrator password each time !!!

Sorry for my English....

I'm working in an IT Department consist of large number
of computers divided in several workgroup.
I've got one PC that really annoying me..
The PC's belong to a workgroup consist of 11 PCs with
Windows XP Profesional. One PC's connected into a HP
LaserJet 1200, and it's shared so the others can use it.
There's nothing unussual with the setup. After the
Windows XP Profesional's installed, then I installed the
HP with USB port and shared it.
What is annoying me is when the other computers try to
connect to the HP printer it asked for a username and
password and only can be fill with administrator password
to have the printer works in the other computer.
But it's not just it, every morning --- when all the
computer's turned on for work --- it have to be set
again !!!
So every morning I'm "travelling" from one computer to
the others just to set the shared printer !!!
When I'm trying to have the HP printer in my computer
which is in a different workgroup, it's just the same.
Once again, I believe there's nothing wrong with the
setting ( the security setting allows everyone to print
and so with the port used to share).
I've never found this problem when sharing the printer,
compare to another workgroup with the same conditions,
there's no problem !
I'm trying to get help from Microsoft Support, but it
just said " YOUR WINXP IS THE OEM PRODUCT SO WE CAN'T
HELP YOU "....holly...
But let the Microsoft goes with their own rule, cause I
believe you guys would help me out.

Thank You