Uninstall magic: MSIZap and MSIInv

Like many of you, my laptop is very “dirty”… I tend to install the latest pre-release builds when they come out… occasionally there are bugs that make it uninstall not even work. Usually what happens is a go to install a newer version of a product and it says there is already an older one installed (or the install fails in some obtuse way). But of course ARP (that’s Add\Remove Programs for the uninitiated among us) shows no entry for the older version.

In the past the only way out of this is to flatten the machine. But recently I found a couple of very cool commandline tools that can really help save the day. And even better those tools are available (but unsupported) for you use. Here is how to use them:

1. Download msizap.zip from www.huydao.net/setup/msizap.zip and unzip to get msizap.exe

2. From the command line window, run the following command to manually remove the previous installation of Avalon or Indigo:

a. For Avalon, run msizap.exe {397F147C-882E-4E9D-92D2-FE1D61E2729A}

b. For Indigo, run msizap.exe {C350D87C-7B67-43E2-B717-E9ADABE2F631}


If you are not sure what products that you need to uninstall, please download the www.huydao.net/setup/msiinv.zip and unzip it to get msiinv.exe. Run this tool in the command line window and send the output in the text file to us. The output file will provide the information on products installed on your box. We can then pinpoint the exact products that you need to remove using msizap.exe {GUID}.

If you are a beta junky, I recommend running msiinv.exe regularly just to clean up your machine. In fact I’d love to hear what old bits you find on your machine with this tool… I know I found a few very old entries that felt good to clean up…


Update (3-04-09):

See updated info at:


Msiinv.exe is a tool developed outside of Microsoft and is available from http://www.huydao.net/setup/msiinv.zip. An old post from Aaron Stebner describes some common use. http://blogs.msdn.com/astebner/archive/2005/07/01/434814.aspx