Ok I'm an idiot, heres my sign (:
I installed PCLinuxOS 2007 fine. I found several tweaks and tried them.
I set the resolution to a higher resolution than the default and it looked
lots better but then picked the next level up 1600 x 1200 and now I get the error on boot.
Please be kind. I have looked for several hours to find the way to go
back to the old setting. I can get to the sh prompt but don't have a clue from there.

thanks

pass linux vga=791 to the kernel on boot

just add the line to your lilo config
like, vga = 791, update lilo, and you have 1024x768 (16bit) if I remember correctly

Thanks.
Now I know that I don't know anything about passing something to the kernal or what a lilo config is.

Appreciate the attempt though.

Okay. Try using xrandr command

xrandr -s 1024x760

I assume that the error occurs when X starts (when you expect the graphical login screen.

Press <ctrl><alt><Fx> (where x=1..6) when the system has booted. You should be taken to a console where you can login.
Edit /etc/X11/xorg.conf and removed the resolution 1600x1200 from any line that contains it. It's in the section screen, usually at the end of the file.

If you're not familiar with vi, you can use e.g. nano to edit it. You need root privileges to edit the file; I think your distro uses sudo, so you might have to preceed the commands below with sudo.

The first line makes a backup, the second one starts the editor.

In the example below, I have highlighted the line that you have to look for.

Once done, press <ctrl><alt><F7> to return to X and press <ctrl><alt><backspace> to restart X.

PS Next time, check the specs before fiddling Older monitors don't have protection and can die when you go outside the spec.