In the previous post Filling up NTFS partition forever without admin privileges I described the method to fill all free space on an NTFS partition without administrator privileges and without creating any large suspicious files. However, "forever" in the title was too strong a word, so I continued to search for solutions to cleanup the clogged $Secure file. Finally, I found this can be done quite simply: you need to use the standard Windows CHKDSK utility! I would've never thought that it had such a feature. Apparently, it was added in around 2009 in the KB919241 update.