>>Hi,
>>Is it possible that bad programming with VFP will cause bad sector on harddisk, and certain files will be lost/dissapear??
>>
>>If not, any possiblity?
>
>The only case where I heard that software could harm hardware was Commodore 128, more than a dozen years ago, where a certain machine code sequence was able to burn one chip. Never heard of any of those later or before.
>
>The code to create a bad sector should have access to disk's internal logic, which is probably feasible in theory, but is practically impossible to do with p-code.

Actually, the mechanism to mark a bad sector doesn't involve much beyond the ability to manipulate the FAT on FAT12, FAT16 and FAT32 volumes; DeviceIoControl() is certainly capable of talking to the disk-level driver and doing this. And since FAT isn't terribly secure, a devious and nasty programmer could simple jumble both copies of the FAT in an interesting fashion by determinging the location of each FAT on the volume, a simple enough mechanism!

And I'm not even being creative...