In VPOP3 v7 or later, then ending the 'pg_dump.exe' process from Windows' Task Manager should stop the backup process totally.
In VPOP3 v5/6, then if just end the 'pg_dump.exe' process, then any ongoing database tasks to extract the data will not end until they have completed (which may be a long time), so the following batch file will end the back-end database task as well as the pg_dump.exe process.
Save this in the VPOP3 installation directory as a file such as 'endbackup.cmd'
@ECHO OFF SETLOCAL CALL psqlparams.cmd SET PGPASSWORD=pgsqlpass taskkill /f /im:pg_dump.exe "%PSQLPATH%\psql" -U postgres -c "select pg_cancel_backend((select procpid from pg_stat_activity where application_name='pg_dump'));" vpop3 SET PGPASSWORD=
Or download the batch file here: endbackup.cmd
Save it to the VPOP3 directory and run it from a command prompt (run “as an administrator”)