The problem:  Diablo won't let you save a multiplayer character on one
machine and load it on another..  Nor will it allow you to back up
multiplayer characters.

The solution:  Use my Diablo fixer utility to copy or backup saved game
files from one machine to another.  Then change your network machine name
to activate the characters.  Here's how to do it:

Suppose that you want to copy a character from home to work.

1) At home, open your Windows Control Panels from the Start Menu->Settings
   option.  Double-click on the Network icon.  Choose the Identification
   tab from the Network Control Panel.  Write down your Computer Name.

2) Now open the Windows folder on your hard drive.  From the View menu
   at the top of the window, choose the Options menu choice.  Choose the
   View tab and mark the Show All Files option.

3) You should see some hidden files in the Windows folder show up as
   DLINFO_*.DRV, where * equals a number from 0 to 9.  DLINFO_0.DRV is the
   first saved game, DLINFO_1.DRV is the second and so on.  (Note: These
   characters are listed in reverse order in Diablo's character selection
   screen).  Copy the desired saved game file from the Windows directory
   to a floppy disk.  Rename the file on the floppy to something else,
   such as MYGAME.DRV.

4) Bring the floppy disk to work.  Copy the saved game file from the
   floppy to the Windows folder of your hard drive.  If you renamed it
   properly, you won't overwrite any Diablo files at work yet.

5) You must have a saved Diablo game on your hard drive at work to
   overwrite with your new saved game file from home.  If you don't, then
   load Diablo and save a dummy network character.

6) Now open a DOS shell and run my DIAB_FIX.EXE utility with the following
   parameters:  DIAB_FIX <source> <destination>.  For example, if you want
   to overwrite the character in the first save slot at work, then type
   DIAB_FIX MYGAME.DRV DLINFO_0.DRV.

7) The last step is to rename your network machine name at work to the
   same name as home.  Go to the Network Control Panel just as before.
   Select the Computer Name from the Identification tab and type in the
   name you wrote down in step 1 (It's always a good idea to write down the
   current name at work, so that you can change it back when you are done
   playing Diablo).

When you load Diablo at work, your saved game file from home will now be
present!  Note:  Any games at work will disappear temporarily until you
rename your network machine name back to normal.  Don't create any new
characters at work during this time or you run the risk of blowing away
the old ones that were present before.

Now for the hacker type who would like to know some more information about
how Diablo saves it's network games:

In the Windows registry is an entry for Diablo under
HKEY_LOCAL_MACHINE\SOFTWARE\Blizzard Entertainment\Diablo.  Every time a
multiplayer character is generated, some protection information is
written into the Video Player registry entry under Diablo.  When the game is
first installed, this table is empty (well it has some repeating garbage in
it).  Saved games are written to the Windows folder as DLINFO_*.DRV, where
* equals a number from 0 to 9.  For every DLINFO_*.DRV file, the corresponding
slot in the Video Player registry table is filled with some time/date stamp
information.  A slot is four 32-bit words in length.

The format of the saved game file (DLINFO_*.DRV) is as follows:  The file size
is always 66935 bytes long.  Bytes 0 - 65650 are generally the same from
game to game (at least in the early levels).  Byte 65644 appears to be the
start of some compressed header information.  Bytes 65650 - 66935 are always
different, except for a few hundred bytes at the end of the file which seem
to be unimportant garbage/filler.  This important data is almost certainly
compressed, as any change to it causes an error in the file.  A quick hunt
through the executable reveals that Blizzard has licensed PKWARE, so the
compression is likely in zip format.

If you modify the saved game file, Diablo checks the date/time stamp
against the information in the registry.  If they don't match, Diablo will
inform you that it is taking corrective action, then it will either recover
your character's basic stats and delete your inventory or it will delete
the saved game altogether if it thinks it has been hacked.  Your machine name
is also saved into the character file.  Diablo will not complain about any
files that were saved under a different network machine name, but they won't
show up in the saved game list.  They only show up when the machine name
exactly matches the one in the saved game.

      - Gary

P.S. If you haven't purchased 3DO's Game Guru yet, run out and buy it.  The
Game Guru is the best tool for doing this kind of hacking work.