You may not need to install IE 7.0.
http://www.my-debugbar.com/wiki/IETester/HomePage may work for you. Note I haven't used this.
>I have read somewhere that the disabled attribute is not supported in IE, prior version 8. That would explain. However, to test that, I would need to install IE 7 somewhere. I will add more input to this once I can simulate it.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer