Is there a chance that adding a printer to a computer on your network will disconnected this computer from the LAN, if there already is another printer of the same or a similar model connected to another computer on the network?

Example 1:

Added a new computer to a wireless network a few weeks ago, everything was working fine, the new computer went online just fine, until I added the Lexmark printer to it. Then, everything was still working fine, only this computer couldn't connect to the network anymore. Another computer on the network had a Compaq-branded, Lexmark-made printer installed, from the same series.

Example 2
This here computer I'm using is connected to a "classic" LAN: router-->hub-->computers.
I installed an old HP 700 series printer on this computer after my cool Canon 6000 threw a 7. The instant the printer was recognized, installed and setup, up pops a box telling me "You now have the IP address 192.168.something or other, and the subnet mask 255.255.0.0". Now that won't do me any good, 10.0.0.***, sn mask 255.255.255.0 was working just fine, and that's the way I had set it up anyway.
Try as I might, as long as the HP 700 was connected to my copmputer, I couldn't get online. Punchline: another computer on the LAN has a HP 800. As soon as I disconnected the HP 700, everything was fine.

I never heard of such a thing, but twice in row, under almost exactly the same circumstances sounds a bit suspicious. Then again, I never "studied" computer science, I just make a living of it ;)

What did you name the printer port when you set up the second HP printer?  HP TCP/IP requires that it be something totally unique from the other already existing printer port name.  If the existing port is named, say, HP800, you need to name the new printer something totally different that does not even start with an "H".  Maybe something like "700 Printer". Otherwise, it will rename itself to the existing printer name and you could have a conflict. Try setting it up with a new name and see if that helps.

HP DeskJet 722c on mine, and HP DeskJet 820Cse on the other one, both connected to the respective parallel ports in ECP mode.



You might be right there, no doubt. But this still leaves me looking for an explanation why the same happened in example 1, where I had a Lexmark Z 2x, and a Compaq IJ650, and both named that way. The Lexy and the Compaq were almost the same model.

What operating system are you using on these computers?  Are the printers connected directly to each PC and then shared, or are they network printers?

XP Home on the new computer in example one, 98SE on the others.

XP Pro on all the computers in example 2.

All printers are/were directly connected to the computers and then shared.

Need more information before I can help.

What Operating system on both Computers ?

Is this a cable/Modem Wireless Router.  I use a similar setup at home for 4 PCs ?  Does assign IP addresses via DHCP ?

I guess the other wireless setup is an Access Point, that does not have DHCP capability.  So need to know this.

I am assuming it is the router with DHCP and your PCs are getting IPs from it.

Also from your second reply - You are actually adding printers to each PCs local parallel port right ?

I just do not want to confuse answers - and hence need to know answers to above to answer them, if interrested.

> What Operating system on both Computers ?

Example One: I don't care anymore, it's not mine, I just quoted it because a similar thing happened as in Example Two: add a printer of a model similar to one already present in the LAN, and the client with the new printer can't access the LAN anymore. That network was NOT designed by me, I was "ordered" to build it with those silly Intel Anypoint USB thingies

Example Two:

A normal phone cable running from the phone jack to the DSL router (Cisco 675, in CAP mode: router, firewall, DHCP server all-in-one), from there, a patch CAT5 cable to a Linksys hub, from there, CAT5 patch cables to the network cards in the client PCs, all running WinXP. The router has the internal IP 10.0.0.1, subnet mask 255.255.255.0, IPs for the PCs get assigned by the DHCP server, all in the 10.0.0.* range. But one can override this and assign a fixed internal IP to a PC (network properties on the client PC), too, adding the ISPs DNS servers to the entry.

> Also from your second reply - You are
> actually adding printers to each PCs local
> parallel port right ?

Yep, that's right.

> I just do not want to confuse answers

LOL, I'm confused enough as it is ;)

I'm pretty perplexed by your problem, myself.  When you set up the printer, did you set it up as a local printer using LPT1?  It sounds like it's trying to use TCP/IP printing instead of your standard shared printer configuration.  Try removing the printer and setting it up again, making sure that you select "Local printer" and "LPT1".  Let us know if anything different happens this time.