Does .net 4.5 work side by side with .net 4.0?

.net .net-4.0 .net-4.5
Vaccano picture Vaccano · May 24, 2012 · Viewed 20.5k times · Source

I am interested in installing the .NET 4.5.

But I have heard that it is an In-Place upgrade.

Since the users at my company uses Windows XP. I can't release any client side apps that use .NET 4.5.

I know I can target .net 4.0 when I code, but, if I install .net 4.5, is there risk of things working on my machine that will not work on a Windows XP machine (that only has .net 4.0)?

(By the way, I looked but did not see this question asked. If it has been asked, please point me to it and I will try to delete this one.)

Answer

user743382 picture user743382 · May 25, 2012

Yes, there are risks of the sort you describe. The .NET 4.0 interface is unchanged, so if you target .NET 4.0, your program will compile and run on XP with .NET 4.0, but the .NET 4.5 implementation of .NET 4.0 contains bugfixes as well. If you rely on .NET Framework not being buggy, and the only available .NET Framework for XP is buggy, your program is going to experience those bugs. I've had this happen with Entity Framework, but there could be other bug fixes as well.

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