Replace a file from MSI

Question

I am planning to replace a DLL file within the MSI file. Is there any way to do it without effecting the MSI installation

Answer 1

InstEdit (http://www.instedit.com/) does work, but it is not an intuitive tool. You do not have to have the plus version, the basic works for this. Just completed using it. Here's the process.

1. Take old MSI and install it to get all the original targets of install.

2. copy all install targets to working directory with your current MSI.

3. open InstEdit and open the MSI (or just drag/drop MSI into InstEdit interface)

4. Open the Tables tab (see image)

5. Click the Media item and you'll see some info on the right

6. Right-click in the right-side window and choose Rebuild Selected CABs.

7. Once you've completed a successful rebuild, you need to go to File...Save As... and save the MSI file so that your changes are incorporated into the new MSI file. NOTE: Save As... is the best option here because I noticed that if you do a regular Save... then it seems to make the final MSI larger -- as if it keeps old components and adds the new ones. The Save As... option creates a smaller MSI.

If you replace the old item in the directory where all of the items for the MSI are found, then when you click Rebuild Selected CABs it will import the newer version of the item automatically and rebuild your CAB.

Errors are cryptic, but if you read them closely you can figure it out and it does work. I replaced a EXE in the MSI with a newly built version.

EDIT

It's been almost 1 year and I came back to remind myself how the InstEd tool works. However, I also stumbled upon an error that you may encounter also so I want to add the additional information.

When you attempt to [Rebuild Selected CABs] you may get an error which looks like the following:

This is somewhat of a cryptic error. InstEd is attempting to tell you that you need the CommonFilesFolder created at the location you are attempting to rebuild the CABs from. Then place the Main.exe in that folder. It is also looking for Main.ico in that same folder.

All you need to do is copy the target .exe and .ico (or any files mentioned) into the CommonFilesFolder and run the rebuild again and it will work.

Answer 2

First off, you might want to check out other alternatives than modifying the MSI directly. This is rarely a good way to go but you may have your reasons. For other options, check out MSDN on patches.

But if you are going to modify it directly, check out this blog entry. It explains how to use Orca, InstEdit, MSIdb, and IExpress to extract the CAB, decompress the CAB, replace the file, recompress and attach the CAB file back into the MSI.

Answer 3

Try InstEdit from http://apps.instedit.com/, but i`m not sure if it is possible to replace file inside msi package. Also you can take a look at Microsoft Orca msi editor that comes with Windows SDK.