Can I use the latest .NET framework on Windows XP or 7?

Question

I'm developing an application that must run on Windows XP,7,8 (desktop mode). Which version of .net can I use?

If this version is not a default part of XP or Windows 7, is it a good idea to include it in my application installer?

Solution

You can use the latest version of .NET (at the time of writing) on Windows XP.

.NET 4.5 is not supported on XP. System requirements for .NET 4.5.

.NET 4.0 is supported on XP.

You should expect to have to install the framework when you install your application though. The dotNetInstaller is good for this (although there are other ways too).

There may well be certain classes or methods in the .NET framework that require a higher version of Windows than XP/Vista/7 etc. But you will have to check these case-by-case.