Question

The code:

Console.WriteLine(Environment.Version);

returns identical results (2.0.50727.5448) for .NET Framework 2.0, 3.0, and 3.5 SP1. How do I learn the exact version of the installed .NET platform?

Answer 1

You need to read registry keys to detect versions at service pack granularity. This article explains what key/value pairs you need to look for.

For example, you can tell 3.5 from 3.5 SP1 by looking at values inside

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5

“plain” 3.5 has Install = 1, while SP1 has SP >=1.

Scroll to the bottom of the article at the link to see the entire table.