Micrososft .Net Framework 3.0 x86 Installion Problem in Vista

Hi All

I am new to Vista as well as Dot Net .(3.0)

I tried to install Dot Net by clicking on the set up file "dotnetfx3"

I got the below error "

"You must use "Turn Windows features on or off" in the Contrl Panel to install or configure Micrososft .Net Framework 3.0 x86

I have tried selecting /deselecting the corresponding options in the control panel but still no luck.

Could you please advise me how to resolve this issue.

Many thanks in advance.
Bobby