What is Microsoft .NET Framework and what does it do? It is in my updates but is it necessary? XPSP2?

The Microsoft .NET Framework is a (large) block of runtime routines used to support applications (like Vista itself) as well as a host of other applications, utilities etc.

Do you need to install the Framework? Nope, you don't. However, if you do, you'll save time later when you want to install an application that needs it. Yes, there are several versions (four or more at this point). If an app needs it, it will include the setup routine. It takes up only disk space until it's needed.

hth

u dont need it if none of ur programs say u need it
if u download a new program that uses it then u need it

I'm not sure about what it does but, yes it's important to your computer I think it helps your computer to function properly...look up on google for more information..

The Microsoft .NET Framework is a software component that is a part of Microsoft Windows operating systems. It has a large library of pre-coded solutions to common program requirements, and manages the execution of programs written specifically for the framework. The .NET Framework is a key Microsoft offering, and is intended to be used by most new applications created for the Windows platform.

Some programs need the .NET framework to be able to run, as they use functions from the .NET framework. Updating the .NET framework simply makes it more secure and stable, therefore it is well worth running those updates, but it is not necessary not unless one of your programs specifically say you need a certain version of the .NET framework to run(very unliklely)