Due to some dependencies on the latest debugger engine, if you are upgrading IISState from a previous version the following steps will need to be performed.

Upgrading via MSI from previous standalone MSI file:
1) Run Add/Remove programs and remove IISState. This will leave any symbols/dumps that you have.
2) Install via the new .msi file.

Upgrading via MSI from the IIS Resource Kit:
1) Install the new .msi file. This will not migrate symbols/dumps into the new directory.
2) To preserve previously cached files, you may copy IISState (and all dll's found there) from c:\iisstate to the installation directory (default: C:\Program Files\IIS Resources\IISState).

Upgrading via .zip from previous standalone msi or .zip file:
1) Download the latest debuggers from http://www.microsoft.com/whdc/ddk/debugging/default.mspx.
2) Place the new IISState in the \debugging tools for windows\ directory.