Q: Permanently delete files or folders from a Windows 7 local hard drive? I heard some people mention that files or folders are deleted from local hard drive for good, there is no tracing back. Is that really true?
If not, how do I permanently delete files or folders from it? I have a sensitive data on a local hard drive and I want to make sure nobody will be able to see that file or folders. I am told that would ALT + TAB delete would be permanently delete for good from the computer? 

A: Permanently is a very strong word, and there are different ways to look at it.


*

*Simple file deletion on Windows will send it to the trash bin, where it usually stays for 30 days until it's removed by Windows.

*If you press ShiftDelete the file will be "permanently" (as far as Windows knows) deleted from windows directly, without going to the trash bin. However,

*There are several easy-to-use programs which recover files removed from the trash bin. This is possible because when a file is deleted by windows, one way to see it is that it was removed from the file index, but it's still recorded in the hard drive. 

*The next step to "more-permanent" deletion would be writing a new file on the same allocated space, but that's not something you easily control. Another option would be formatting the disk.

*Formatting might permanently delete the file, or not. The same programs mentioned above usually have tools to recover formatted disks, and they generally work, even if not completely, but some files are restored.

*Even if these programs aren't able to recover the file, there's always the possibility that an expert could try to recover it using more advanced techniques, which is what sometimes happen in forensic analysis of criminal investigations.

*AFAIK, the only 100% guaranteed way to delete a file is physically destroying the hard drive. Open it up, tear it apart, break it into pieces, burn it in hell's fire. That should do it.

*Unless of course it was ever replicated online (by email or online folders services, like Google Drive, SkyDrive, DropBox, etc. If so, it's beyond your reach).

