ConCat/Split V6

ConCat/Split is a Windows Explorer context menu extension that provides two complementary facilities:

  1. A split facility that lets you easily convert a single large file into several smaller ones. You can copy these smaller files onto removable media such as a memory card, floppy disks, or CDs, or send them through email systems that will not allow large attachments.
  2. A file concatenation facility that performs the same operation as the command line "copy /b SrcFile1+SrcFile2 [+SrcFileN] DestnFile" operation. With ConCat, you can append any number of files and store the result as a new file, or overwrite one of the original files.

ConCat runs under Windows XP, Windows Vista, Windows 7 (and the server variants of those operating systems), and is available for x86 (32-bit) and x64 (64-bit) systems.

ConCat - Copyright © 1996-2012 JD Design, All Rights Reserved


We recommend that you unzip the file and run the Setup.exe from your hard disk.

You need to run the installation from an account with access to Administrator privileges.

If you don't have an up-to-date copy of the Windows Installer, the setup program may download it.

The last step of Setup informs you that ConCat is installed and briefly tells you how to use it. If you're upgrading an existing version, we recommend that you log off and back on again, or restart your computer to ensure Explorer has unloaded the prior version.

If your system administrator has applied the EnforceShellExtensionSecurity policy to limit the use of shell extensions to approved ones, they will need to add ConCat to that list in the registry:

Create a REG_SZ value whose name is "{B2D4ADE0-0C85-11cf-872F-444553540000}" under the HKLM\Software\Microsoft\Windows\CurrentVersion\Shell Extensions\Approved branch.

Administration Installation

The installer supports the MSI administrative installation options.

For example:

msiexec /jm concat.msi

"Advertises" ConCat on all the machine's users Programs menu items. When a user invokes the Start, Programs, JD Design, ConCat, ConCat-Split Documentation option, the installation of ConCat will complete.


msiexec /a concat.msi

Performs an "administrative" installation to a shared network location.

Files Installed

ConCat setup installs files to the following directories:

%ProgramFiles%\JD Design\ConCatThe main installation directory.
Contains the core program files, including the ConCat shell extension DLL.
...\docThe documentation directory, contains this document and related image files.

Setup will also add relevant registry entries and Start menu items.

How Do You Use ConCat?


Use Windows Explorer and select the file that you want to split. Display the context menu by right-clicking (the secondary mouse button), or use the Explorer window's File menu. Choose the "Split File..." menu item to display the Split dialog box:

Split Context Menu

Split Dialog

Operation of this dialog box is straightforward. The "Split Size" group radio buttons populate the combo box list with either:

  1. Common drive sizes, or
  2. The free space size of any removable drives on your system that have media inserted in them. When you select this option, it may take a few seconds to find what's available. If there are no removable drives with media inserted , the combo list will be empty.

You can enter a custom size setting by typing a value (in KB) in the edit field of the combo box.

The destination names field shows the range of file names that you will get from the split operation. The default location for the split files is the same location as the original file, however you can change the location and name of the destination files if you use the Change button.

To perform the split operation, press the "Split File" button.

Note: the split operation is non-destructive; it will not delete your original file.


For ease of use we recommend that you copy the individual files that you have previously split into a folder on your hard disk.

Using Windows Explorer, select the files that you want to concatenate. Display the context menu by right-clicking (the secondary mouse button), or use the Explorer window's File menu. Choose the "Concatenate Files..." menu item to display the Concatenate dialog box.

Concatenate Context Menu

Concatenate Dialog 

Important: The selected order of the files in the Explorer window determines the order that the files are copied. The first file is always the one with the focus (the fine dotted rectangle around it). Here is how you can ensure that you get the files copied in the correct order:

  1. Select the first file.
  2. Hold down the shift key and click the last file that you want.
  3. Release the shift key and right-click on the first selected item to bring up the context menu.
  4. Choose the "Concatenate Files..." item to display the Concatenate Files dialog box.
  5. The order that the files appear in the "Copy" list box, is the order that they will be concatenated. Ensure that this is the order that you want.

In an unregistered version, the default destination file name is the same as the first selected file. If you want to alter this, change the "To" file name before you press the OK button.

Context Menu Bitmap Display

If you'd prefer not to have the bitmap displayed on the Explorer context menu, add the following registry setting:

HKEY_CURRENT_USER\Software\JD Design\ConCat

Create a DWORD value named "Options" and set the value to 0 to disable the bitmap.

Registered Version Features

The registered version of ConCat adds the following features:


The easiest way to register is online using one of the secure payment facilities on our web site.

When you receive your registration information, enter your registered name and number into the About dialog box. You can access this dialog from the main ConCat dialog About button.

You must enter the information exactly as it appears. The case, spaces, and punctuation of the name are significant, The registration number is composed of the characters 0-9, A-F and again, the case of the letters is significant. If you register the set of utilities, be sure to use the correct registration number for each product.

You can check that registration has worked by re-displaying the About box from the main dialog. When the product is successfully registered your registration name is displayed in the About dialog rather than the entry fields.


Any updates to the current version are free to registered users by downloading the latest version from our web site. You may need to email us for an updated registration number.


Locate the "ConCat" item in the Control Panel, Add/Remove Programs list.

Revision History


We maintain a list of frequently asked questions on our web site. If you  have a technical question, please check there to see if you can find an answer before contacting us.

We will post the latest versions of our utilities on our web site as soon as they are available, so please take a look to keep up to date and to see what other software and services we offer.

Web Site:

If you have any suggestions for improvements to any of our utilities, please contact us via email (our up-to-date address is on our web site's contacts page). It's always good to hear from people using our products, and we appreciate your taking the time to tell us.

JD Design