问题
Can these framework versions work and play well on the same server? Meaning that can IIS support two application pools where one pool is configured with .NET 4.0 and the other with .NET 1.1.
EDIT: This question is concerned with IIS 7.
回答1:
Yes, you can have 1.1, 2.0 and 4.0 CLRs all running in the same IIS instance, they are intentionally side-by-side installs to facilitate this, you'll have 3 options in the dropdown for your application pool .Net versions, one for each CLR version.
回答2:
yes - you can target the .net version of a specific framework in IIS [i use IIS 7] and can right click over an application pool > go to advanced settings and then choose .net framework version
回答3:
Yes, you can do this via IIS or via command line:
appcmd set apppool /apppool.name: OldStuff /managedRuntimeVersion:v1.1
appcmd set apppool /apppool.name: NewStuff /managedRuntimeVersion:v4.0
来源：https://stackoverflow.com/questions/3611399/net-4-0-framework-on-same-server-as-net-1-1