I have uploaded an excel file from my desk top to the Windows Live (HOTMAIL?) office suite. When I try to open the file I get an error that says my system is not supported. My system passes all of the listed criteria except for one. That is a plug in from Firefox. The instructions say to go to the Firefox menu, click on tools then plug-ins. Of course when I go to tools plug-ins is not immediately available, but when I do go to plug-ins, I am to click on Microsoft Office 2010. This plug in is supposed to allow earlier versions of office documents to be viewed as well as Office 2010. The plug-in is not available. When I search the Firefox website I am not able to find such a plug-in.

I am using Microsoft XP, Office 2007 and the version of Firefox prior to V4. V4 does not support all of my e-mail clients so am not able to use V4.