Microsoft recently released a hotfix to address a vulnerability in ASP.NET for the .NET Framework 2.0.  Security bulletin MS06-033 contains more details about this hotfix.

This is one of the first hotfixes that has been released for the .NET Framework 2.0 (possibly the first, but I'm not sure).  There have been some issues that we've seen with the installation of this hotfix, and as a result the following knowledge base articles have been published:

• Install of MS06-033 fails with error code 0x643
• Install of MS06-033 fails with error code 1324 - The folder 'Program Files' contains an invalid character
• Install of MS06-033 fails if Windows Installer version 3.1 or higher is not already installed

The set of steps that I typically use when a .NET Framework hotfix fails is not listed in any of the above knowledge base articles, so I thought I'd list them here in case they are useful to anyone out there:

1. Click on the Start menu, choose Run, type appwiz.cpl and click OK
2. Locate the item named Microsoft .NET Framework 2.0 (the name will contain x64 or ia64 on 64-bit operating systems) and click the Change/Remove button
3. Choose the Repair option to attempt to repair/reinstall the .NET Framework 2.0
4. Download and attempt to install the .NET Framework hotfix by running the setup package directly instead of using Windows Update.  Running it directly will allow the service pack setup to display more useful error dialogs instead of having Windows Update suppress them

If repairing the .NET Framework 2.0 does not solve this issue, then I would suggest trying the following steps as a last resort:

1. Download the .NET Framework cleanup tool and choose to cleanup the .NET Framework 2.0
2. Download and re-install the .NET Framework 2.0
3. Download and attempt to install the .NET Framework hotfix by running the setup package directly instead of using Windows Update.  Running it directly will allow the service pack setup to display more useful error dialogs instead of having Windows Update suppress them

<update date="7/22/2006"> Updated workaround steps to suggest repairing the .NET Framework 2.0 before resorting to uninstalling and reinstalling it </update>