We would collect the Computer or Laptop (Server would remain on site) and take a complete image of the drive in question. This way we eliminate the chances of physical and logical damage to the original data. Then using our tools we set about recovering anything still recoverable onto suitable media. To avoid the perils of Data Recovery it is highly recommended that all users employ some form of Backup Solution.
Imagine if all your company data was gone one day. Could your company survive? Imagine if all those family photos disappeared.