Some WIX extension tags write rows to CreateFolder table, e.g. <iis:WebAppPool>, <util:User>, <util:XmlConfig>. As the official MSI document says, a patch can be Not uninstallable if it contains new rows in the CreateFolder table. I think such extensions can be implemented without the usage of the CreateFolder table. It‘s really bad to block patch uninstall just because the usage of these extensions. There is a screenshot which shows my CreateFolder table in Orca.exe.
Some WIX extension tags write rows to CreateFolder table which lead to Not-Uninstallable Patch
原文：http://blog.csdn.net/pkudzy/article/details/38752839
