You don't need the net framework to install any drivers.  It sounds like you were trying to download the drivers using the Dell Download manager.  The download manager has been problems and should not be used.  Only download each driver needed individually. 

As far as installing on a Dell there is a specific sequence that needs to be followed, (1) Install Windows (2) Install Dell Desktop System Software (3) Install Motherboard Chipset Drivers (4) Install Device Drivers including Video, Dell sound drivers, Ethernet, etc. 

"You don't need the net framework to install any drivers."

Thats wrong.

The ATI Catalyst Drivers have required  DOTNET 1.1 AND 2.0 and higher.

Some other vendors use DOTNET also because Java is not installed by default on windows anymore

and they needed a scripting language.

You can use the MSI installer clean up tool to remove dotnet.

Then install DOTNET 1.1

Then Install DOTNET 2.0

Then install DOTNET 3.0

Then install DOT NET 1.X,2.X,3.5 updater/patch/  :p

Then install DOT NET 1,X,2.X, 3.X sp1/patch/   :p

mon problème j'ai fait un formatage a mon pc dell Inspiron 15 i3 et j'ai beaucoup de drivers qui veules pas installer et comme le .NET Framework , donne moi la solution s'il vous plaît  

The stand-alone executable packages contain all the components that are required to install the .NET Framework 4 on the specified target platforms. However, these executables do not contain language packs. You can use the stand-alone language packs to install language support.

http://go.microsoft.com/fwlink/?LinkId=181013

The following table lists the stand-alone redistributable packages for each profile and platform.

dotNetFx40_Full_x86_x64.exe