The following scenarios are partially recoverable:

• Restoring Windows® from a recovery CD. The original data on the boot drive will be partially overwritten by files copied from the CD. The percentage of recoverable files is higher for a larger boot partition. For example, it could be between 50% and 80% for a 40-GB partition.
• Accidental deletion of files many days before and the computer has been in use since then.

The following scenarios are poorly recoverable or unrecoverable:

• Restoring a disk image (such as Ghost image) on a wrong drive. The original data on the drive is usually overwritten and unrecoverable.
• A large amount of new data has been created or copied on the subject drive since the data loss incident occurred.
• A file has been edited and saved. The original version is usually not recoverable.
• If a drive is physically faulty and is no longer detected by the computer BIOS or cannot be accessed reliably, the drive may require physical repair. Almost all faulty drives can be repaired but the costs can easily be as high as a few thousand dollars.