FileFiller is an software which lets you create dummy files at (almost) any size. The file's contents can be pseudorandom, filled with zeros or with characters, whose ordinal value you can specify. The software supports FAT12/16/32 and NTFS filesystems; files created in a FAT-formatted volume can be as big as 4GB, and for NTFS up to 80 GB. To speed up the process and to allocate the memory efficiently, use the "Gigabytes" option to create huge files. No installation required.

The license of this software is Freeware, you can free download and free use this disk management software.