I've seen success with exporting the HKEY_LOCAL_MACHINE\Software\ODBC registry key and importing on the new PC, and copying entries from the ODBC.INI on the old to the INI on the new...
These instructions are for System DSNs, see the note at the bottom for User DSNs
Note that all your registry exports have to be in Regedit 4 format if you are moving your ODBC drivers from W2K to any other OS.
1. Export the datasource name - for example, I have "TestingZebra" - (easy to spot in the registry). So I exported the HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\ODBC Data Sources\TestingZebra key to a reg file
use regedit, find the key, highlight, File> Export Registry File, save as Regedit 9x/NT...etc.)
2. Next, export the DSN itself... HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\TestingZebra to a reg file. Note what path the "Driver" subkey in the reg file is referring to. You'll need to put your DLL there on the new PC (or change the referring path).
3. Find the references to your DSN in the ODBC.INI file on your originating system, copy them to the ODBC.INI file on the new PC. (refer to the note in step 2 about paths)
Again, watch the path names...
4. Copy the referenced .DLL file from step 2 to your new PC (also referenced in your ODBC.INI file).
5. Change any path names that are needed in your reg keys so they reflect where your driver is located on your new PC, and import the keys into the system registry.
6. Reboot your PC, and the drivers shouldthen appear.
These instructions are for System DSNs, if you are looking for User DSNs, go into HKEY_CURRENT_USER (log in as the user account who owns the DSN) in step 1. and 2. rather than LOCAL MACHINE.