Question : Network tools

A friend has a small business and has asked me to assist with some networking issues.  I'll be honest, I know enough to be dangerous when it comes to networking.
I have:
3 pcs & 1 notebook
A belkin router
A hp 3600 printer, networked.

The printer was added to each pc by add printer, local, tcpip, and specifying the ip address I had manually entered on the printer. I was told by belkin ts to enter 192.168.2.10 in the printer. It was all working fine when I set it up but I've been told that subsequently the printing has been intermittant. I have to go back up there this afternoon to fix it.
I was wondering if there are any free tools available that might make this process a whole lot easier to manage & test?
All suggestions welcome!

Answer : Network tools

When you suspect a network communication problem always work your way up from the hardware. Your troubleshooting technique should demonstrate that the hardware is working and then that TCP/IP is correctly configured. Since there is no DNS server netbios is being used for name resolution unless you have an LMHosts file configured. Command line tools like nslookup, nbtstat, arp, ping and the ipconfig command can demonstrate that the hardware is working and that TCP/IP is configured correctly. Here is a Microsoft guide for troubleshooting a simple network.
http://support.microsoft.com/kb/308007/
Also look at any firewalls included with antivirus software. Most permit you to configure a trusted local network. You can temporarily disable your firewall  as a troubleshooting technique.

Then look at Windows configuration. Once you have demonstrated that all devices are communicating at the TCP/IP level then check that file and printer sharing is enabled and that all devices are in the same workgroup. You haven't mentioned what OS you are working with. I am assuming XP. If Vista then there are additional steps.