On Sat, 3 May 2025, Brian Knittel via cctalk wrote: Start by erasing everything on the disk that you want to get rid of. THEN, before doing anything else, fill up the disk completely, with large files and small ones. If you don't have files to do that with, open your word processor, and type "404 " a few thousand times; you can cut and paste to get more, with less manual typing. Then, erase those, and fill it up again, with different files. hexadecimal E5 is a good filler. If you want, do that a few more times. THEN "defrag" the disk. Fill it once more, then erase the filler. All of the space previously used by the "sensitive" files will have been overwritten.

On 4/05/2025 6:46 am, Brian Knittel via cctalk wrote: As a few others have pointed out the easiest way to erase files to they can't be undeleted using a simple utility is to delete them and then fill up the disk with a large file containin zeros. Or simply keep copying an existing inocuous file until you run out od disk space (not difficult if you copy it, then copy both copies and then all four, eight and so on. It works on all systems. HOWEVER this does not destroy data to the point where people like me can't possibly recover anything given enough time and incentive. Don't assume this is good enough for security sentiive infomration. I won't go into the details (buy the book!) but one easy example is data on bad sectors that have been mapped out and marked "do not use" by the OS, but are very likely still readable if you try hard. I suggest a balanced view. Is anyone going to spend time and money trying to recover the deleted data, and if so, how much? Unless it's a lot of time and money then deleting the files and zeroing the empty space is probably good enough. Regards, Frank.