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Introduction to PHYLock

Introduction to PHYLock

PHYLock is a software component that functions as an add-on to Image for Windows. Designed to run under Windows 2000 and later, PHYLock enables Image for Windows to maintain a consistent backup of an unlocked partition or volume.

Note that consistency is based on a point in time. That is, the backup created by Image for Windows with the help of PHYLock will be a "snapshot" of the source partition as it exists at a given point in time. This "point in time" coincides with the moment that PHYLock becomes active and the imaging process begins.

Image for Windows attempts to choose an optimal point in time at which to activate PHYLock. This is done, in part, by requiring a write-free period of time prior to the onset of imaging. However, there is no guarantee that all software programs, internal caches, and so forth are in a clean state at that point. (That statement is true of all backup software that can be used to backup a partition that is in use.)

PHYLock Compatibility Notes

PHYLock 2.04+ - Requires Image for Windows 2.00 or later
PHYLock 2.01 - Requires Image for Windows 1.61 or later
PHYLock 2.00 - Requires Image for Windows 1.60 or later

PHYLock Download

The latest version of PHYLock is always included in the Image for Windows distribution. Alternatively, you may download PHYLock independently:

PHYLock (Compatible with Image for Windows V1)
PHYLock (Compatible with Image for Windows V2)

PHYLock Installation

If you wish to install PHYLock via the Image for Windows distribution, simply run the Image for Windows setup program; an option to install PHYLock is provided during setup.

If you wish to install PHYLock from one of the archives linked to in the PHYLock Download section above, proceed as follows:

  1. Extract the files in the ZIP archive to a folder.

  2. Run setup.exe from that folder.
  • You may use setup.exe /i to perform a silent installation.

Related Knowledge Base Articles

PHYLock Must be Reinstalled After Upgrading to Windows Vista or Windows 7/8.x/10

Message: "Unable to Copy the Required Component from the Current Directory to the Windows Driver Directory" During PHYLock Install

PHYLock Uninstallation

Run the setup program as outlined in the PHYLock Installation section above and respond to the prompt shown.

  • You may use setup.exe /u to perform a silent uninstallation.

General Tips

  • If you don't have a use for the Last Access timestamp placed on files and you're using the NTFS file system, you can disable it by browsing to HKLM\SYSTEM\CurrentControlSet\Control\FileSystem and setting the DWORD value NtfsDisableLastAccessUpdate to 1.

  • When setting up a batch file to start IFW you may find the net command helpful in controlling services. In particular, "net stop", "net start", "net pause", and "net continue". Many services use "net pause" as a signal to flush data to the disk, although you'd have to check with the maker of the software to know for sure. Image for Windows V2 offers services.ins to control services with a finer granularity.

  • If you have a problems with the cache size not being big enough in RAM mode, you may wish to turn off the byte-for-byte validation option. When the option is not used, the cache will be cleared of any data that has already been backed up. In particular, if you're saving the image to the same NTFS volume being backed up (or backing up an NTFS volume in general) then it may be log file that is causing the cache size problem. You can reduce the log file to something like 4MB if that volume doesn't routinely have lots of activity/updating. There is a slight delay when the log file fills up and rolls over; adjust accordingly. To see the current size of the log file you may use the command chkdsk [volume] /l (e.g. chkdsk c: /l) and to adjust the size you may use chkdsk [volume] /l:kbsize (e.g. chkdsk d: /l:4096).


Windows NT Issues

Problem Booting after Installation

If you have a problem booting the operating system the first time after installing PHYLock, press the space bar immediately when the following message is displayed during boot:

Press spacebar NOW to invoke Hardware Profile/Last Known Good menu

Windows 2000, XP, Vista or Windows 7/8.x/10 Issues

Problem Booting after Installation

If you have a problem booting the operating system the first time after installing PHYLock, press the F8 key during boot if the "Please select the operating system to start" message appears. Otherwise, press F8 as soon as the OS begins to boot. From the "Advanced Options Menu" select the "Last Known Good Configuration" item and press enter.

"Last Known Good Configuration" is not available from the standard Windows 8.x/10 troubleshooting options, but you can access System Restore points.

Networking Problems after Installation

While highly unlikely, if you happen to experience problems trying to access or serve network shares after installation:

Adjust the IRPStackSize registry value. See this KB article for details: Network Shares Do Not Appear or Are Inaccessible After Installing PHYLock

General Issues


PHYLock is installed but IFW still says it can't obtain a lock.


  1. Ensure you're using Windows NT/2000/XP/2003/Vista or Windows 7/8.x/10 (i.e. a Windows NT-based OS).

  2. Check that PHYLock is enabled in Image for Windows' settings.

  3. Uninstall any third party software/drivers that also provide snapshot or disk protection services. Many of them are ill behaved and will block requests intended for PHYLock.

  4. Enable the Use VSS When Available option. This doesn't require a reboot and may work when another program is blocking PHYLock.

Related Knowledge Base Articles

Understanding PHYLock Errors

Cannot Obtain a Lock While Attempting to Image a Drive

Message "Unable to Obtain a Lock on Drive [n]:" when Creating or Restoring an Image

Error Message "PHYLock failed to cache all changes" when Using Image for Windows and PHYLock Under Windows Vista


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