.NET 4.5 RC Framework CLR – Windows XP compatibility

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Problem :

My question in short is: “Can .NET framework 4.5 be installed on Windows XP machines?”

I have the following MSDN link:

.NET Framework Versions and Dependencies

Each new version of the .NET Framework retains features from the previous versions and adds new features. The CLR is identified by its own version number. Some versions of the .NET Framework include a new version of the CLR, but others use an earlier version. For example, the .NET Framework 4 includes CLR 4, but the .NET Framework 3.5 includes CLR 2.0. (There was no version 3 of the CLR.) Although the .NET Framework 4.5 RC is an in-place update of the .NET Framework 4, the underlying CLR version number is 4.5.

The documentation goes on to say you can only install .NET Framework 4, .NET Framework 3.5 SP1, .NET Framework 2.0 SP2 on Windows XP Professional and Windows XP Home Edition (i.e no 4.5 mentioned).

I’ve read in other places that .NET 4.5 can be installed on Win XP. So is this documentation just referring to 4.5RC (not the final 4.5 framework).

My issue is, are we not able to deploy apps built on 4.5 in XP machines. Will Microsoft release a service pack? (unlikely since they don’t support XP)

p.s. a couple of interesting articles on the subject:

.NET 4.5 is an in-place upgrade to .NET 4.0

.NET 4.5 breaking changes – compatibility issues between the .NET Framework 4 and the .NET Framework 4.5 R

Solution :

From looking at the .NET Framework System Requirements docs – I think you’re out of luck.


According to the doc, it’s certain that it wasn’t in the test matrix, you won’t get support for the installation. The installer may still work assuming it doesn’t explicitly block unsupported OS’. YMMV.

XP is in extended life-support through 2014 – you’re only going to see critical security fixes, not new features like this.


As discussed in this link No, .NET 4.5 will not be supported by Windows XP.

Anyone can vote for making Windows XP supported on .net framework 4.5 here

Just use Mono http://www.mono-project.com/Main_Page

It is XP compatible.

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