Windows file explorer says that my SSD has 125 Gb free out of 237 Gb. So I went into the drive and checked how much storage every file uses. After I subtracted the Gb of all the files from the 227 Gb of the SSD, I calculated that the SSD should have had 150 GB available. That's 25 more than what is displaying. So, what's happening here? Are there any hidden files, or is file explorer not accurate with the calculation of storage?