OS :
Windows
open cmd
fsutil file createnew file_name 1073741824 // 1GB
fsutil file createnew file_name 1048576 // 1MB
fsutil file createnew file_name 1024 // 1KB
fsutil file createnew file_name 1 // 1B
Reference:
https://www.foolegg.com/how-to-create-a-empty-file-of-a-specific-size-in-windows/