Network Printing

Hi,
I have a Xp computer. It is on Domain. configured printers locally (LPT1 and USB)
I shared the printer for everyone.
But When I am trying to configure for other computers I cannot. Printer session is not responding.
Even i tried to open through the network neighborhood I am getting error message as follows
” computer name or share name not found.”
Did I forgot to enable some thing.
I checked file and print sharing.
I have another XP PC i shared, But i did in January.
Is anything to do windows Update or Any shares are not opened, Please help me out