Can a server have more than one .Net frameworks?

Can a server have more than one .Net frameworks. Our Application is made in .Net 3.5 but server is having old versions.So can we install one more framework on server and it will not affect other applications.

Thanks

Yes, you can install multiple versions of .Net side by side.

NOTE: If you have asp.net applications in IIS, you have to configure which version you want to use in your application.

In reality, .NET 3.5 is not a separate *version* - it is additions to the 2.* CLI. The main decision here is 2.* or 4.*. If this is a web application, you can configure IIS to decide which CLI to use.

So: if the "old versions" are 2.*, then installing .NET 3.5 **will** impact the existing applications, and the service packs **could** cause behaviour changes in some edge cases (pretty unlikely most of the time). More likely: the service packs that come with 3.5 will *fix* some existing BCL bugs.

A better option, though, might be to move your new app to 4.0; that **is** separate to the older versions, so you get an independent .NET engine. Perhaps just as important: you'll get all the current libraries and fixes.

Yes, you can have all versions of .NET installed.

Note: Version 3.5 is just some added libraries, the core is still framework 2.0.

If it's a web application, you have to have a separate application pool for each framework version you use.