In Windows, you can run SQL loader from command prompt via the following ways:
1. Command Line Reference
sqlldr scott/tiger@orcl data=C:\data\emp.csv control=c:\ctl\empctl.ctl log=c:\temp\sqllog.log
SQL*Loader: Release 188.8.131.52.0 - Production on Mon Jul 9 14:48:54 2018 Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. Commit point reached - logical record count 14
2. Using batch script
Save the above sqlldr command in the batch file with extension .bat. and execute it by typing batch file name.