Peter Laudati posted about migrating applications from .Net 1.1 to .Net 2.0. In doing so, he listed the different behaviours of .Net applications when running on computers with different versions of the .Net Framework installed:

Application type Computer with 1.1 Computer with 2.0 Computer with 1.1 and 2.0
1.1 stand-alone application (Web or Microsoft Windows client) Loads with 1.1 Loads with 2.0 Loads with 1.1
2.0 stand-alone application (Web or Microsoft Windows client) Fails Loads with 2.0 Loads with 2.0
1.1 add-in to a native application (such as Office or Internet Explorer) Loads with 1.1 Loads with 2.0 Loads with 2.0 unless the process is configured to run against 1.1
2.0 add-in to a native application (such as Office or Internet Explorer) Fails Loads with 2.0 Loads with 2.0

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