Patch - MSP

MSP (Patch)

A patch is an updated version for an application. You can obtain patches from the software manufacturers or internal developers of the original program. You can update an existing application without uninstalling the product. This preserves the customizations of the installation and potentially reduces the cost to make the change. The patch might change only a few bytes of a single application file, making it more efficient to distribute those few bytes, as opposed to uninstalling and redeploying the entire product. At the other extreme, a patch might change all of the files and registry keys in a product.

A patch package (.msp) does not include a database like a regular installation package. Instead it contains, at a minimum, one database transform (a transform that adds information to the database of its target installation's .msi package.) Windows Installer uses this information to apply the patch files that are stored in the cabinet file stream of the patch package.

Patch files Contain the information required to transform the previous version of the file into the new version. You can use a single patch file to update one or more old versions of a file.

A patch changes the package code of an .msi file. To allow Windows Installer to perform maintenance operations such as adding, removing, or repairing an installation, the package codes for the installed application and the source must match. Therefore, a computer that still has the original package code installed cannot be maintained by using a patched administrative image until you update the computer.

Patch installation packages comprise the following parts:

· A GUID that uniquely identifies the patch. The GUID for this patch is appended to a list of GUIDs for earlier patches that are replaced by this patch.

· A list of product codes delimited by semicolons, specifying the valid product configurations to which the patch might be applied. targets for this patch.

· A semicolon-delimited list of transform sub-storage names, in the order they are to be applied (sub-storages are described in the following subsection).

· A list of sources delimited by semicolons for this patch.
You can use the command-line option to apply a patch to software installed on a computer

msiexec /p patch.msp REINSTALL=[Feature list] REINSTALLMODE=omus


To patch installations using an administrative image:
1. Create the administrative image, if it does not already exist, with the following command line:
msiexec /a package.msi

2. Update the administrative image by running the following command-line option:
msiexec /a package.msi /p \patch.msp

To remove a patch that you have applied, you must remove the entire application, and then reinstall the application without the patch. There is no way to roll back the changes a patch applies to the original package

if you have installed the patch on the top of the installation of an MSI on a machice then you can uninstall just the patch from the machine using "MSIPATCHREMOVE"

Msiexec /I {0C9840E7-7F0B-C648-10F0-4641926FE463} MSIPATCHREMOVE={EB8C947C-78B2-85A0-644D-86CEEF8E07C0} /qb

Where {0C9840E7-7F0B-C648-10F0-4641926FE463} is the Product Code of the application and ={EB8C947C-78B2-85A0-644D-86CEEF8E07C0} is the Patch GUID

Applying a Patch Package to a Local Installation
msiexec /p patch.msp REINSTALL=ALL REINSTALLMODE=omus

Applying a Patch Package to an Administrative Installation
msiexec /a //server/MNP2000.msi /p MNP2000.msp


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