The process of upgrading FlexWiki 1.8 to version 2.0, is relatively simple. The necessary steps are:

1. Backup all the topic files (*.wiki and *.awiki) and then copy that backup somewhere other than the web server;
2. If you have customized your wiki.css file copy that to a different location on the web server;
3. Copy flexwiki.config (if it exists) to a different location on the web server (I also recommend making a print out of this file for later use);
4. Copy web.config to a different location on the web server;
5. Install .Net Framework 2.0 (if not already installed - Windows Update will offer the file);
6. Install the .Net Framework 2.0 Security Updates using Windows Update;
7. Using the IIS Service Manager, stop the IIS Website where FlexWiki is installed;
8. Delete the files in the /bin directory of your FlexWiki 1.8 installation
9. Download the latest FlexWiki binary package verison of the software (current latest build is 2.0.0.199) webupgrade-release.zip;
10. Extract the files from the zip package into the existing FlexWiki installtion;
11. Review the contents of the file flexwiki.config.template - this file contains details of all the new configuration settings possible for FlexWiki;
12. Edit flexwiki.config to add the new settings you want to include - there is no automated conversion or update of this file (mainly look for the tags DefaultNamespace and NamespaceProviders. The new key <CaptchaKey> is mandatory and must be a valid 16-character hex value. - Note that you don't need the NamespaceMap.xml file anymore as the information is now in flexwiki.config);
13. IMPORTANT - See FlexWikiAuthentication about security of the flexwiki.config file as this file may now be accessed and modified through the FlexWiki Admin pages on the web interface; and
14. Rename the previously copied version of your custom wiki.css file to a local name, e.g. wiki-mysite.css, and copy it to the FlexWiki directory and include this file as the <OverrideStylesheet> in flexwiki.config
15. Change your ASP.net settings for the FlexWiki site from using .NET Framework 1.1 to use .NET Framework 2.0
16. Start the IIS web site where FlexWiki is installed.

Potential Issues

During release testing, one site noted that FlexWiki consumed large amounts of CPU. The developers were unable to reproduce the error, but disabling newsletters (via setting the <NewsletterConfiguration><Enabled> setting to "false" in flexwiki.config) reportedly addressed the problem. If you do encounter this problem please notify the user mailing list, and you may want to disable newsletters while the issue is addressed.

Further Observation: The AssemblyName field in the old NamespaceMap.xml specified the specific version for each namespace, and between that and the guid id field, I wasn't sure that would work. That's good if it does.