FreeBSD 6.0 Installation Problem

[galberti at bellsouth.net]

I am trying to install FreeBSD 6.0 on a ATX Mid Tower desktop machine whose characteristics are listed in the attached file.
The problem encounter is the same4 I encountered when trying to install on the same machine FreeBSD 5.1 in 2003. At that time I gave up and installed a Red Hat Linux 7.0.

The FreeBSD Sysinstall "FDisk Partition Editor" screen shows the following info:

     Disk name: ad0     Disk Geometry: 4998/255/63 Sectors = 80292870 = 39205 MB

 Item         Line 1          Line 2          Line 3           Line 4
 Offset               0                 63      20482875     80276805
 Size                 63     29482812   59793930            16443
 End                 62     20482874   80276804     80293847
 Name      --------           ad0s1           ad0s2             --------
 PType             12               4                    4                  12
 Desc      unused    NTFS/HPPS  Extend. DOS    unused
                                        QNX                 LBA

I used the command "G" to set the drive ad0 geometry to match the geometry shown by the computer BIOS, but I got a message informing that such geometry was incorrect for drive ad0.
Also no change appeared on the "FDisk Partition Editor" that I summoned after the message.
This sequence of inputs and message repeated again after my next couple of attempts.
I do not have a DOS O.S. available, nor an "Ontrack" program suitable for the HDDs installed in the machine to extract  their geometry.
At this point I do not know what to do other then trying to install a new HDD, which, of course, is not my preferred solution at this time.
I also read the ERRATA document, but I did not find any mention to this occurence.
I will thank anyone who can give me some word of wisdom to solve this problem.