I combined your 4 posts into one and removed your email address as a courtesy.
In the future, if no one has yet responded to your post you can edit it to add additional information. Doing that AFTER a response can make things confusing.
Now to respond to your original question. You do not necessarily need ANY versions of netframeworks or you may need all the versions. Programs that need netframeworks need a specific version. Installing the latest version may not be the right one.
As riider has mentioned above, Windows Update will offer up any versions needed for your particular installation.