What is non-destructive data recovery software?

With non-destructive software, no changes are made to data on the drive. No data is ever written, changed, erased or rearranged. Data is only read. This is important in data recovery. Some recovery software actually alters data, which can potentially cause data loss. The basic Windows function of error checking a hard drive might seem harmless, but it too alters data. Destructive methods may lead to recovery of data, but they should only be attempted on a copy of the failing drive.