You would still need a 32 bit Silverlight version because Firefox is a 32 bit application on Windows.

• https://support.mozilla.org/kb/Using+the+Silverlight+plugin+with+Firefox

Your User Agent: Mozilla/5.0 (Windows NT 6.0; WOW64; rv:33.0) Gecko/20100101 Firefox/33.0

As said Firefox for Windows from mozilla.org is a 32-bit application. The WOW64 in UA means it is a 32-bit application on 64-bit Windows.

Before you ask if there will be a Win64 version of Firefox. If all goes well the first phase of having Win64 for Release may be as early as Firefox 37.0 https://wiki.mozilla.org/Firefox/win64

So how do I get a 32 bit version? The Silverlight site has one download available. They claim it will determine which version your computer supports but I continue to get the same message regarding 62 bit. All the blogs I read say that you might have to uninstall all previous versions but I search and don't find any. Any ideas?

So is there a 32 bit version of Silverlight? All download sites imply they will determine which version your system needs....thus I continue to get the same error message. Blogs seem to suggest I need to delete all previous versions of silverlight but I can't see that I have any to uninstall. Thanks.

PJPNovice said

Netflix requires Microsoft Silverlight plug in to view their videos. Every time I try to load it I get the following error message...Your operating system does not support the 64-bit version of Silverlight. I have a 64bit system with Windows Vista Home Premium. Firefox 33.0 is installed. Any suggestions?

I spent three days googling this problem and looking here. Lucky for me I have access to a 32 bit computer running Win 7. I downloaded Silverlight there and copied the file to my 64 bit machine. Installed like a dream! PS Exploder and Chrome seem to have the same problem...