Problem Installing Microsoft .NET framework 3.0 and 3.5

Hey eveveryone! Hope you are all well.

I have a problem with the .net framework versions 3.0 and 3.5.

Basically here is the story. Today was on the computer and to use an editor I needed .net framework 3.5... So off I went to download. Downloaded. Installed. Tried to run the editor, but it didn't work. Asked what the problem might of been and it was likely that it didn't install correctly, so I needed to unistall then re-install.

My problem now, is I 'thought' I was uninstalling 3.5, but infact I was uninstalled 3.0. So through my rush to get it all done i've created more work for myself and I thought it was a simple re-download of 3.0 and install... But it hasn't worked like that.

Everytime I go to install 3.0 I got the message "must turn on windows features" or something along those lines. Had a gander at that and unchecked/unfilled the box, tried again and didn't work... Had a look where the .net framework files are and there was still some odd files sitting there, so I deleted those, tried again and got a bit further... It went to the terms and conditions part, I press yes and it started to install. It got to the end and all I get is an error message saying it was unable to complete.

So to sum up... 3.0 doesn't install. Does anybody know why .net framework 3.0 doesn't install? Anything to do with registry? Files still on computer which shouldn't be?

I am running Windows Vista Ultimate 64-bit, Service Pack 1.

Hope someone can help because this sort of thing will drive me crazy!!!! :cry