Ticklish Techs

As we all know, the main resource for help on Visual Studio and .net is the Microsoft Help Explorer that is installed with Visual Studio. Sometimes it is called the Visual Studio Combined Help Collection. Most of the Microsoft development tools (for example SDKs for Office and Visual Studio) but also tools from other vendors install their help resources into this Explorer.
It is really nice if it works. But on my system I ended up with not only one central Help Explorer but with three, each containing different content. One came with Visual Studio 2005, one with Orcas and another with the Visual Studio SDK. For some reason only the last one showed up the .net-framework help, but every time I pressed F1 in Studio the first one – without the content – opened.
I knew that there is somewhere a settings dialog where you can see the installed content of the Explorer and enable or disable some of it. But Microsoft does a very good job in hiding this dialog. It is shown like any page of the help. To find it just go to the Index and look for “Visual Studio 2005 Combined Help Collection Manager” or for Orcas Beta 2 “…2007…” – I think they will change the name in the final Visual Studio 2008.

[Edit: this seems to be solved in Visual Studio 2008. See this article]

In theory if you create a setup project within Visual Studio, you can set the RemovePreviousVersions to force the created setup to uninstall all previous versions of the same software already install on the target computer. This is a very useful option, but it does not work under all circumstances. But before I go into the problems a brief overview how it should work:

Besides the RemovePreviousVersions flag there are two further properties: UpgradeCode and ProductCode. The UpgradeCode must be the same for all setup projects (that is for the old versions and for the new version). The installer uses this UpgradeCode to detect an older version of the software. The ProductCode must be different for every version, this is uses by the installer to detect different versions of the same software . If you change the Version of an installer Visual Studio creates a new ProductCode.

This works the way described here in the same way described in the product documentation as long as you do not use a Version number below 1.0. If you name your beta and prerelease version something like 0.5 the installer does not recognize an previous version and will not uninstall it, but installs the new version side by side which can be a problem for you installation e.g. if it will be installed in the same directory.

Unfortunately this seem to be a known issue since 2004 or earlier and is not fixed in Visual Studio 2005. The installer looks only for previous Versions greater or equal 1.0 but not for versions less than 1.0.

But there is a workaround. You have to patch the MinVersion in the created msi-file with a tool called orca.exe.

1. Download the Windows Platform SDK – about 400 MB
2. Install it – Full install is about 1 GB but you only need the MSI-SDK parts, so choose the custom installation.
3. In the directory of the SDK you will find an orca.msi – install it
4. Start the orca.exe and open your created msi
5. Got the Upgrade-Table
6. Look for the 1.0.0.0 in the VersionMin-field and change it to somethink like 0.1.0.0
7. Save the changes to the msi