X configuration problem

[Jay O'Brien]

Initial 4.10 installation. Trying to configure XFree86.
from /stand/sysinstall, select Configure | XFree86. 

I THINK I've tried every possible combination. I couldn't 
use the "Fully graphical XFree86 configuration tool" as 
the graphic was partially off-screen and the monitor was 
"out of range". I used the textmode tool and the shell-
script tool, settling on the shell-script tool. After 
agreeing that it should write /etc/X11/XF86, and selecting 
a desktop to use, many different attempts all result in 
this error:

"Error mounting /dev/acd0c on /dist: Input/output error (5)"

And the next screen is:

"An error occurred while adding the package(s) required by 
this desktop type. Please change installation media and/or 
select a different, perhaps simpler, desktop environment 
and try again."

I don't find a /etc/X11/ directory, much less a XF86 file.

Video card is ati XPERT 98, monitor is 1280x1024 LCD.

A suggestion for what to try next?

Jay O'Brien
Rio Linda, CA USA