Installing Client Update Files with OHotFix

Ohotfix.exe is a software program designed to help administrators deploy update files within their organizations. OHotFix works by reading a series of deployment instructions contained in an INI file, and then using those instructions to apply an update to the computer. OHotFix can also check applications on the computer to determine which updates need to be applied, and it can order a group of update files so that an installation is optimized.

Previously, OHotFix and the Windows Installer update files (MSP files) were packaged together in the Microsoft® Office client update releases. This separate release of OHotFix provides a stand-alone copy that can be used to deploy update files for both Office 2000, Office XP, and Office 2003 applications.

OHotFix requires that version 1.1 or higher of Windows Installer be installed on the client computer.


Toolbox     The OHotFix program is packaged in a self-extracting executable (Offinst.exe). You can find this downloadable file on the Office XP Resource Kit Downloads page.


The steps involved in using OHotFix to deploy an update to client computers are as follows:

  • Install the OHotFix program.
  • Extract the Windows Installer update files from the client update EXE packages and install them in a common directory on a network share.
  • Run OHotFix to install the updates.

Installing the OHotFix program

When you download OHotFix, you must specify a folder for the three files that make up the application. For OHotFix to run correctly, all of the files must be installed in a single folder. This same folder must also contain all of the Windows Installer update files (MSP files) to be installed. The following table describes the three files that form the core of OHotFix.

File name Description
Ohotfix.exe The core application file that contains the user interface as well as code for detecting and applying the patches.
Ohotfixr.dll A library file that contains text strings (errors, messages, and so on) used in OHotFix. The file is language-specific and must be localized as appropriate.
Ohotfix.ini A settings file used to control how OHotFix runs. Settings include the following:
  - Type of update
  - Detection parameters
  - Reboot options
  - User settings
  - Logging level
  - Windows Installer version level

Complete information on the settings in the Ohotfix.ini file is contained within the file itself. To view the information, you can open the file with a text editor such as Notepad.

Extracting the client update files

To apply a client update file using OHotFix, you first extract the individual MSP files from the client update EXE package and then run OHotFix from a command line to deploy the update to the computer.

You can extract the files from the client update file by using a command line similar to the following:

C:\path to update file\MyUpdate.exe /c 
/t:C:/folder for extracted files

After you extract the MSP files from the client update package, copy them to the same folder in which you installed the OHotFix files. You can disregard the OHotFix EXE, INI, and DLL files included with the client update package — the new versions provided with this update replace all previous versions.

Managing the updates

When OHotFix runs, it applies all the MSP files in its folder in alphabetical order. You can place as many separate MSP files in the folder as you need. If you are updating a group of computers that are at different states of currency, you can include all of the update files needed by the most out-of-date computer. OHotFix automatically detects if an update file has already been applied to a specific computer, and it does not attempt to reapply a patch to an up-to-dated computer.

By extracting the MSP files and storing them in a permanent folder on a server, you can create a resilient network source for the update. This practice is useful when the user of a client computer accidentally deletes the local MSP file and needs to recover the update. If the local MSP is deleted, Windows Installer looks for the MSP file at the path from which the patch was originally installed. If the network source is available, then Windows Installer recaches the MSP file without failing or prompting the user for the MSP file.

Deploying the updates to client computers

To deploy an update with OHotFix, you run the program separately on each local computer. You can do this by using any of the following methods:

  • Have users run OHotFix from a shared server.
  • Create a logon script.
  • Distribute the program as a batch file.
  • Deploy OHotFix using Microsoft Systems Management Server.
  • Use another software installation tool to distribute OHotFix.

Client computer update files can be kept in a folder on the administrative image, or in any network share that is accessible to all clients on the network. The patches do not need to be stored on a unique server.