Pinter stopped working in Classic

I have a G5 running Sys 10.4.11. I have been using an HP all-in-one 1500.
I had no problems until this morning. I had switched the printer to my Toshiba laptop and had to run the installation software on the Toshiba. I logged on to Mac and a Sys 9 program and tried to print and got a "printer Error" message. I remembered my printer was plugged into the laptop. I shutdown and swapped cables and rebooted the Mac. Printing from Sys 10.4 works fine. When I try to print from any programs in Classic I get "printer error" or "please use chooser to select a printer." I had never gotten this message before when printing worked. I tried selecting any printer with 1500 in the description. Dialog said turn on apple talk," then, "apple talk cannot be opened," then, "to turn on apple talk open Network preferences and turn on Apple Talk." I can't find a folder called Network preferences. If I click on another printer called HPaioPrint, I get <no printer port> <no modem port> and background off, and apple talk active or inactive. I tried reinstalling printer driver, rebooting etc. no help. If I open System Preferences and click on Network, I get a message that "Your network preferences have been changed by another program and I can't get out of the dialog unless I hold my pointer over the red X and hit return and click fast to close the dialog. Anybody have an idea what's going on?

You'll probably have to re-establish the printer connection within classic, access to the choose and network preferences can be found on the classic Apple menu, in chooser and control panels

I guess I was not clear. I had tried using the choose in the Apple menu. When the sys 9 apps said, "please use chooser to select a printer." I tried selecting any printer with 1500 in the description. The dialog said turn on apple talk," I click on AppleTalk Active and I get, "apple talk cannot be opened," then, "to turn on apple talk open Network preferences and turn on Apple Talk." I can't find a folder called Network preferences. If I click on another printer called HPaioPrint, I get <no printer port> <no modem port> and background off, and apple talk active or inactive. I went to the Control Panel Menu as you said and none of the control panels turn on AppleTalk. These are my choices in Control Panels:Adobe Gamma, Appearance, Apple menu Options, Date & Time, Extensions Manager, File Sharing, File Synchronization, General Controls, Internet, Keyboard, Keychain Access, Launcher, Monitors, Numbers, QuickTime Settings, Speech, Startup, DiskText and USB Printer Sharing. When I open USB Sharing clicking strat, stop, has no effect.

Can you reinstall the System Folder, ie. OS 9.2.x (or Classic) because it seems to me that you have a system corruption in OS 9. Pacifist might enable you to reinstall an OS 9 Sys ƒ from your Tiger install disk. [But, see Para 3 below.]

Is your G5 a tower or iMac? If a tower, in your situation I'd install a second and dedicated small hard drive for OS 9. Other than booting with a different HD and OS, it works really well, and you don't get the cross-OS issues.

To the problem with "your network settings have been changed .....", this is a well-documented issue with Tiger, and has come about as a result of an OS update some 6+ months ago. Search this and other forums for advice as to what you can do to cure or work around the problem. Perhaps your printer will work again once you've got the OS situation sorted.