WoWInterface - Need Help with Interface Designer

Hi.

I need Help using the WoW UI Designer (http://www.wowinterface.com/download..._Designer.html)

Whenever I try to run it, it says:

[color=DarkRed]NET Framework Initialization Error

To run this application, you first must install one of the following versions of the .Net Framework:
v2.0.50727
Contact your application publisher for instructions about obtaining the appropriate version of the .Net Framework.
Could anybody help? That would be nice :(

-Flamingo