Posted 21 September 2008 - 09:08 AM
As far as I'm aware, whether a quick or full format has been done doesn't alter the possibility of recovery. A quick format just re-initialises the filesystem data structures, a full format also does a media integrity check, but this is a read-only check so nothing on the drive is altered unless a bad sector is found. (In a read-only integrity check, the CRC of the contents of each sector is calculated and compared with the CRC recorded when the sector was written. This confirms the sector is good as it still has a true copy of the last data that was written into it.) In either case the original file contents and filesystem metadata still exist, so there's a high likelihood of recovery.
If major data has been copied onto the drive, such as the case of a Windows installation, some of the previously existing locations will have been overwritten with new data. That will cause two problems with recovery. Some of where the old filesystem metadata was will now describe the new files, so in most cases those old files can't be identified and reconstructed. Secondly, new file contents is being written into the data area of the drive, and if this goes over where recoverable files were previously located, software recovery will produce a file, but at least some of it now contains the data from a newly written file, not the one that was previously there. The situation will be even worse if a defrag was done following the Windows install.
Hence garmanma's warning about not using the drive for anything else before attempting recovery.
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