When you delete a file, operating system doesn't go through every file manually. Instead, it has an index of all the files in every folder that it can refer to because it is much faster. Windows Explorer uses that index to show you the names of the files. The common problem with sensitive data is that deleted files are not really erased and so may be recovered by interested parties. That is because most file systems only remove the link to data.
When a file is "deleted", the directory entry remains unchanged, preserving most of the deleted file's name, along with its time stamp, file length and most importantly its physical location on the disk. The list of disk clusters occupied by the file will, however, be erased from the File Allocation Table, marking those sectors available for use by other files created or modified thereafter.
CS Wiper will erase files and folders from your hard drive the way impossible to recover. This will help you prevent sensitive data such as passwords, bank accounts and other personal data when you sealing your old computer or need to protect data on regular basis.