First of all, I realise there are a fair few related questions on many other sites, in addition to Microsoft Support pages. I have spent many hours on this issue, and this is where I stand and what I know/have been able to achieve:
  • I have an application written in Visual Basic Express 2010
  • There is an AxWebBrowser control in the main form
  • On computers with Excel 2010 installed (and running Windows XP), I've managed to get the application working fine; I realised that I needed to change the registry so that the Excel documents would open within the AxWebBrowser instead of in a separate Excel window (see this Windows Support page)
  • On computers with Excel Viewer installed (and running Windows 7), the Excel documents continue to open in a separate Excel Viewer window
  • On the computers with Excel Viewer installed, there are eight additional registry subkeys with the names: ExcelViewer.Macrosheet.8, ExcelViewer.Sheet.12, ExcelViewer.Sheet.8, ExcelViewer.SheetBinaryMacroEnabled.12, ExcelViewer.SheetMacroEnabled.12, ExcelViewer.Template.12, ExcelViewer.Template.8, ExcelViewer.TemplateMacroEnabled.12
  • The fix given in on the aforementioned Windows Support page requires adding a new key in four subkeys (for Excel, not ExcelViewer) via "BrowserFlags"=dword:80000A00
  • I realise this value is a hexadecimal value. In regedit the Data value for these keys is 0x80000a00 (2147486208)
  • The hexadecimal value is different for Word, PowerPoint, and Excel in the aforementioned fix

I therefore assume there is a particular hexadecimal value I need in order to stop the Excel documents opening in a separate Excel Viewer window on those computers on which it is installed. I've tried using the Excel value 0x80000a00 in just .Sheet.8, .Sheet.12, .SheetMacroEnabled.12, and .SheetBinaryMacroEnabled.12, as per the fix for Excel. I've also tried putting it in all eight subkeys. None of this has worked, so I can only assume I need a different hexadecimal value.

I've scoured the net for a possible list of values that would help me with this, but to no avail. It seems this sort of information is kept under wraps. So now I'm appealing to all of you (and I hope this is the right section of the forum) in the hopes that somebody can provide a solution or at least point me in the right direction.

Let me make it clear that I don't believe the issue to be anything to do with how I've implementing the AxWebBrowser in VB 2010. I included that information as background information. I also don't think it's an issue with Windows XP compared to Windows 7. I've read many Windows Support pages for help with this issue and nothing seems to address the problem of Excel Viewer specifically. My last port of call, I suppose, would be to guess registry values. The largest hex value I've seen for BrowserFlags with respect to Microsoft Office products is 0x80000a00 for Excel. Even if I were to guess every value between 0x80000000 and 0x80000a00, there would be around 2500 values and a tedious week of work.

Many thanks for even reading this far - I realise that was quite a dense question. Any help would be greatly appreciated.