Just import first log2db.sql from prelude server and then import log2db_04162004.sql from C1 server
make sure you are importing to lin2log database - not master or somewhere else
then check if you've set up your DSN correctly
then check if you supplied a correct info to your L2LOG.exe when you've started it first time.
if not sure delete a HKEY_Local_Machine/Software/Project_L2/L2Log key (don't remember exact key names) and run it again