A list of terms used in this page and their explanation can be found here.

Start-up status display

During startup DiskPatch will display the following screen:



This screen can help you identify important problems quickly. A number of things are checked before DiskPatch shows the main interface, to make sure that any problems that may interfere with the recovery process are identified as quickly as possible. If no problems are detected this screen will disappear automatically (or you can press a key to speed this up). If problems are found that may pose a risk to the recovery, the screen will remain and you will need to press a key to continue. The affected disk(s) will flash in red. Make sure to address the problems that are indicated. Contact DIY DataRecovery support if you need assistance.

The results are indicated as follows:

The following items are checked :

• UDMA driver: when starting from the DiskPatch boot disk you are asked if you wish to load the included UDMA driver. This driver may speed up certain operations for certain disks (read more here). You should not load the driver if the disk you wish to work with has read- or write problems; only load the driver if the disk is mechanically sound. For that reason DiskPatch checks if the UDMA driver is loaded, and if detected DiskPatch will notify you. If a yellow exclamation mark is displayed the driver is loaded. If a green checkmark is displayed the driver is not loaded. Not loading the driver guarantees maximum compatibility, so that's why the green checkmark appears if the driver is not active.
• Disk health: during startup the health for all disks is checked. If problems were found a red exclamation mark will be displayed here and you should find out what raised the alarm. If a yellow exclamation mark is displayed the disks could not be checked so no details about disk health are available. If the green checkmark appears no problems were found. To check the disk's health the SMART attributes are read and verified. Read more about this here.
  what to do if a problem is detected: the DiskPatch distribution includes a SMART tool that will generate a disk health report. You can run it from the DiskPatch boot disk's Main menu (select the option "create a S.M.A.R.T. report") that is displayed when starting from the DiskPatch boot disk. Read more here. If disk health is seriously low (and you need the data that is on that disk) you should clone the disk as soon as possible.
• The 128Gb barrier: some older BIOS versions have problems addressing the space beyond 128Gb on large disks. This may result in data getting 'wrapped around' when writing past the 128Gb barrier; the 128Gb barrier is treated as if it is the starting point of the disk. So data that is written past 128Gb will end up somewhere at the start of the disk, with the obvious chance of destroying data in that location.
  what to do if a problem is detected: this is a serious problem that needs to be addressed as soon as it is identified. You can read more about this here. Possible solutions can be a BIOS update, or getting the BIOS to recognize the disk correctly. If this can not be resolved for the PC that holds the disk, the disk should be removed and placed in a PC that will recognize it correctly before attempting further repairs.
• Disk Geometry: at certain times (especially when dealing with disks that have mechanical problems) a disk's geometry may not be detected correctly. DiskPatch checks the geometry values it receives from the BIOS to see if they are likely to be valid. If the values are found to be incorrect DiskPatch will attempt to correct them by calculating the geometry settings. If this occurs a yellow exclamation mark will be displayed. In most cases no follow-up actions are required. You can check a disk's geometry settings by looking at the disk information bar. If you believe the geometry settings are still incorrect you can change the settings in the options screen.
• Disk overlay: DiskPatch looks for disk overlay software. If found, this could indicate that the overlay software was not correctly loaded, or was active in the past but is not loaded now.
  what to do if a problem is detected: disk overlay software can interfere with the repairs; make sure the overlay software is loaded if needed. Or, if the overlay software is not needed anymore (because the current PC has no problem recognizing the entire disk), make sure it is not loaded or removed.
• Number of read retries: if the number of read retries is '0' you will be notified.
  what to do if a problem is detected: if you wish you can set the read retries to a higher value than '0' (recommended for most scenarios).

Other startup messages and/or errors

MBR Read Error

If the MBR (Master Boot Record, the very first sector on the disk) can not be accessed, DiskPatch will display the following message:

The MBR is perhaps the most important sector on the disk; it contains a number of things (like the partition table and the boot code) that any Operating System needs to start the computer and access the data on the disk. If the MBR is not accessible it is not possible to restore normal access to the disk. There are three possible ways to deal with this:

• Clone the disk and then use DiskPatch on the cloned disk.
• Attempt to repair the sector. By trying to write to the MBR sector you can trigger the disk's internal sector repair system, which would replace the bad MBR with a sector from the spare pool. Look at the disk surface scan section for more information (essentially you'd need to run a surface scan for one sector, the MBR, which is sector 0).
  Please note that it is also possible that performing a 'Partition Table rebuild' may actually fix the problem; when the MBR is saved by DiskPatch this may trigger the disk's internal repair system. In general it should be safe to try this first, unless the disk is having many more read problems besides the MBR.
• Use a read-only recovery tool like iRecover to copy the data from the disk to a safe place, then replace the disk.

DiskPatch checks the MBR numerous times during a session, so this message may pop up more than once.
MBR read errors may indicate bigger problems with the disk, so you should check the disk's health before you continue.

Problems with writing files

DiskPatch needs a location to write its files. Undo files, log files and other data needs to be saved to guarantee a carefree repair session. If files can't be saved (because for instance DiskPatch is running from CD) a message will be displayed:

Select a location for the files but make sure you DO NOT select the drive that needs to be recovered.
Please note that if you have started your PC using the bootable CD/DVD, the "A:" drive will be the CD/DVD drive and can not be used to save files.
Make sure you select the same location for the files if you perform more repair sessions later. DiskPatch will help you recognize a location that was used previously, the text "(previous session data found)" will be displayed for a location if earlier session data was found there.
You also have the option of disabling logging and file saving altogether. This is not recommended, but there are situations where logging is not desired. For instance, if you are cloning a disk that has a lot of bad areas, disabling logging is actually beneficial because DiskPatch won't have to report every error it encounters. Read more on how and why here.

If no drives are found you will see a warning screen:

At this point all file writing will be disabled. If you need files to be saved (if you wish to create a log file or need undo functionality) you can use a USB stick or key to save the files. Read more about this here.

EFI / GUID partition type encountered

The most commonly used way to partition a disk is the MBR method. This means that the MBR (the first sector on a disk) contains a table that describes the partitions that are on the disk. In recent years a new method has been developed: the GUID or GPT table. This system no longer relies on the MBR and is therefore capable of addressing much more space and partitions. A large area at the start of the disk is reserved for the GUID partition table. So where the MBR is just one sector, the GUID partition table can be a number of sectors. You can read more about this on the Microsoft TechNet website.

When DiskPatch repairs a partition table it is always rebuilt as a MBR type partition table, GUID type partitions are not supported. This means that areas of the disk that may contain GUID partition data are overwritten when a repair is performed. For this reason DiskPatch warns you when a GUID partition setup is encountered:

If you continue past this warning and perform a repair, the GUID partition description data (NOT the actual partitions!) might be damaged. This doesn't have to be as problematic as it sounds: if you have GUID type partitions but you can't access them, rebuilding the partition table with DiskPatch (which will result in a MBR type partition layout) may very well give you access again. You could say that you would have converted the GUID partition setup to a MBR setup [*]. In such case it wouldn't be all that dramatic that the GUID partition description data is gone; you have access to the partitions and can copy your data to a safe place. After that you could always repartition the disk as GUID if you wish.

[*] This doesn't mean that a repair can be used to convert a GUID setup to a MBR setup.