Cannot connect Mac to PC network

I have a network set up that consists of 2 pc desktops, 1 pc laptop (all running win xp), 2 printers, and one mac powerbook using OS X 10.4.8.

From my PC, I can view and access the Mac (and all other PCs) just fine. However, when I try to access a PC from the Mac, it asks me for a username and password. Previously, I did not have one set up on the PC. I was unable to access the PC. I set up a username/pswd and tried again but I have had no luck. I have even tried making the mac and pc credentials the same. Any suggestions? Mainly I am interested in printing wirelessly, but since it asks me for a username and password to access, I can't even add the printer.

Please help :> Google is failing me this time!

Just a thought from my limited experience:

It seems like most of the time when I attempt to use afp to connect to a pc no matter what credentials I pass to that pc it will deny me. If you have an account set up on the PC and use the smb protocol, that solved the problem for me.

Example:
Attempting to access a shared folder on a pc named "Bob1"
In the finder, click Go and select "Connect to Server".
In the server address type "smb://Bob1"
It will ask for a username and password, use the one you already created on the PC.
BAM, you ...should have access to the shared folders.

Good luck.

That is something I had actually tried...Still doesn't work. I tried using my lan IP address/computer name...just the computer name, just the ip address. Nothing. :/ Thanks for the suggestion anyway.

when you say your mac asked for a username/password and you hadn't one set up and went and then set up a username/password.....

Did you just go back to the mac and when it asked for the name/password you just typed the newly created ones?

Or did you go through the process of setting the mac up from scratch?

I'm not really sure if this is entirely neccessary but I am trying to help.

I set a password on my PC...my mac already had one. So I didn't set the mac up from scratch..