Hi, I just learned about fsutil file createnew C:\Blank.File 10000000.
I created a 50gb file in 1 second I went to properties and it said its 50gb size on disk.
CCleaner takes a good hour and a half for 70gb fsutil takes 1 second..
I was wondering the difference between the two other then CCleaner being exact and fsutil having to manually enter size.

Please tell me the difference between the two.

Probably the difference between allocating and overwriting. For a start, CC will write 70 gb of zeroes on your disk, which is no mean task. And Fsutil? As far as I can see it will create a few entries in the various file and space management tables, and write no data at all.