Quickly Generate Large Test Files in Windows

Never download another 100mb test file or waste time searching for a large file.  Sometimes you need a large file fast to test data transfers or disk performance. Windows includes a utility that allows you to quickly generate a file of any size instantly.
Open an administrative level command prompt.

Run the following command:

fsutil file createnew <file> <size in bytes>

For example, this command will create a 1GB file called 1gb.test on my desktop:

fsutil file create new c:usersstevedesktop1gb.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

[youtube http://www.youtube.com/watch?v=VridBEW1MXg]