Quickly generate dummy files for testing file copies on windows

 https://tweaks.com/windows/62755/quickly-generate-large-test-files-in-windows/

fsutil file createnew 1gb.test 1073741824

The key is to input the size of the file in bytes so here are some common file sizes to save you from math:

1 MB = 1048576 bytes

100 MB = 104857600 bytes

1 GB = 1073741824 bytes

10 GB = 10737418240 bytes

100 GB =107374182400 bytes

1 TB = 1099511627776 bytes

10 TB =10995116277760 bytes