Installing .NET 3.5 SP1 Problems

Hi!

I have trouble installing Microsoft .NET framework 3.5 SP1 

it says You must use "Turn Windows features on or off" in the Control Panel to install or configure Microsoft .NET framework 3.5 SP1

now my headache starts here

please look at the picture on the link

http://social.technet.microsoft.com/Forums/getfile/481684

as you can see there is no .NET 3.5.1 here . . . . hell there's a lot that's missing here. What should i do?

i need .NET 3.5 for installing some Applications and Programs 

and i hope it wont involve re installing windows 7 because the problematic PC is used for work

hope you can help me ^_^ thanks