Re format is a disire to or find it nessacery to erase all the data from your hard drive/drives and then to restore that data to the clean hard drives,
Reasons for this could be that your commputer has problems and is running/ badly or not running at all.or you have decided to install a new operating system/motherboard etc .if you are installing a new operating system then you would only need to re format the drive where your operating system will go.

Im sure there must be other reasons Ive missed but I hope this helps.

Personally I hate to perform this task.:)

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