Firefox is always a 32 bit application (even on 64 bit Windows), so you need a 32 bit version of a plugin to make it work with Firefox.

I tried running the 32 bit plug-in for FireFox and the message I received was "This 32 bit product may only be installed on a 32 bit edition of Windows".

I think you already have the plugin installed. The More System Details doesn't show the full information, but you can check on the Add-ons page. Either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Plugins. Then look for "Microsoft Office 2010."

Assuming that is the case, is the plugin you are trying to install something different? Do you have a link to more information about it?

I noticed something a little bit annoying that might not affect you, but just in case. If you have changed a setting in Firefox so that Firefox's right-click context menu is never suppressed by a site, then Firefox's menu appears in front of the menu that lets you open a document in Office. To reveal SkyDrive's/OneDrive's menu in this situation, right-click the site's menu below Firefox's menu and offset to the right. Then you can click on the visible part of the site's menu.

In answer to your first response; yes there is an "Microsoft Office 2010" plug-in, however when I go to the "Check Mozilla Plug-ins Site" it indicates that the status of the "Microsoft Office 2010" plug-in along with several other plug-ins including "Photo Gallery", "iTunes Application Detector" and "Google Updater" are "unknown". A "Research" website is included for each of the unknown status plug-ins. This then took me to a site where the "Microsoft Office 2010" plug-in could be downloaded, however as stated previously, the only download is for 32 bit edition of Windows which will not load on my PC.

Regarding your second suggestion. I'm not sure I fully understand what you want me to do, but I did right mouse clicked on an excel file in OneDrive which produced a drop down menu that included "open in Excel". I tried right mouse clicking again on that drop down menu and nothing happened. When I right mouse clicked off the first drop down menu (below and to the right) the first drop down menu disappeared and was replaced by a FireFox menu. I then tried right mouse clicking on top of the OneDrive menu bar items and again a Firefox drop down menu appeared, albeit different than the drop down menu that appeared in the body of the page.

Don't worry about updating your plugin independent from your regular Office updates. Just keep Office 2010 up-to-date and it should take care of the plugins as part of that process.

Regarding the second message, it sounds like the annoying issue I have does not affect you. You should be able to simply click on Open in Excel. Does that work?

No it doesn't open. See above responses.

I'm not clear on the above responses...

If you right-click the document to display the SkyDrive/OneDrive menu, then click (not right-click) Open in Excel, what happens? Nothing? Does Firefox display an error message? Does Excel display an error message?

When I try to open the document in Excel, the first message I get is "Some files can harm your computer. If the file information looks suspicious or you do not fully trust the source, do not open the file" . I then select OK and the following error message appears "An unexpected error has occurred" and the file does not open. Instead a window appears offering three choices "My workbook opened successfully" or if there were issues "Open in Excel Web App" or "Get Microsoft Office 2013".

Can you tell which program is giving you the message that "An unexpected error has occurred"? It's possible that the title bar of the error will reveal this.

Here is the progression of screens I get opening an Excel document. (I did not already have Excel open when I started, and I have not allowed Windows to save my Live ID.)

My progression is as shown below.

Thanks for the screen shots. You never see the splash screen showing that Excel is starting? If you already have Excel open, trying closing it to see whether Excel at least is firing up.

So one possibility is that the plugin is not correctly handing off the URL to Office. Another possibility is a problem in Office, or whatever program/service it uses to grab that URL. This level of interprocess debugging is beyond me, unfortunately.

I was going to suggest Microsoft support, but I think you already have a thread going: Why can't I open webdocs using Office 2010 - Microsoft Community.

Hmm, I noticed your warning dialog says "Microsoft Office" and mine says "Open Document". What browser were you using for your screen shots?

FireFox.

In answer to your post of 12:04, I tried using IE and have the same problem, so I guess the problem is with MicroSoft to resolve.