When using JETPACK to compact a database, never have a TEMP.MDB in the directory of the .MDB you are compacting, as JETPACK use TEMP.MDB as working storage and will delete it.
To compact a WINS database, run a batch file which contains:
net stop WINS
JETPACK WINS.MDB WRK.MDB
net start WINS
To compact a DHCP database, run a batch file which contains:
net stop DHCPSERVER
JETPACK DHCP.MDB WRK.MDB
net start DHCPSERVER
During the process, JETPACK compacts your database to WRK.MDB, deletes your .MDB, and then renames WRK.MDB.