If you have "Delete to Recicle Bin" enabled and you haven't wiped it already, it can be simply restored by clicking on recycle bin. Then select deleted files and recover it.
But if you have this option disabled you have to do it by another complicated way such system restore(from certain restore point) or with some special software (you surely know that if files are deleted they aren't physicaly removed(0's to harddisk written), but only first letter is renamed to "?" or nothing and file is moved sent to end of physical drive(in TOC too).).
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