how can .net framework 2.0 replace 1.1?

i use mathcad 13 in my daily life, and this software need the support from .net framework 1.1. after installing vb express, .net framework 2.0 is installed, and i uninstalled 1.1. however, mathcad can now run after that, and i have to reinstall 1.1. it is not so amusing to see both of the two different vision of .net framework in my computer, how can i replace 1.1 with 2.0 correctly?
[386 byte] By [Lavaor] at [2007-12-17]
# 1
Because later .NET versions can contain changes that break applications built for a previous .NET version, the .NET Framework is designed to run side-by-side. That is, .NET 1.0, 1.1 and 2.0 can all happily be installed on the same system without affecting each other.

This means that on a system with .NET 1.1 and .NET 2.0 installed, .NET 1.1 applications use the .NET 1.1 Framework, whereas .NET 2.0 applications use the .NET 2.0 Framework.

DavidM.Kean at 2007-9-8 > top of Msdn Tech,Visual Studio Express Editions,Visual Basic 2005 Express Edition...
# 2
well, although it is not so good to see both of them, it seems that we can do nothing to it.

but how this will tobe later? maybe we will have to install 1.1,1.2,2.0,2.1,3.0,3.1..... all of the different vision of .net framework in my computer?

Lavaor at 2007-9-8 > top of Msdn Tech,Visual Studio Express Editions,Visual Basic 2005 Express Edition...
# 3
You have different runtimes for VB Classic (3, 4, 5, 6) and they all have to reside on your machine at the same time. And different DLL's for other languages, so why not for .NET?
edburdo at 2007-9-8 > top of Msdn Tech,Visual Studio Express Editions,Visual Basic 2005 Express Edition...