|According you Microsoft's website, if you're using Vista 32 or 64bit, you must have Service Pack 2 installed.|
Check to make sure you have SP2 for Vista installed by right-clicking on 'Computer' in your start menu or your desktop and clicking on 'Properties.' Toward the top of the window that pops up it should say your operating system along with any service packs you have installed.
If you need to Download and install SP2 for Vista, click the link to Microsoft's website below:
After you have installed SP2, install IE9 by downloading it from Microsoft by clicking on the link below.
Law of Logical Argument: Anything is possible if you don't know what you're talking about.