My comment above shows it's not that hard to get the Excel add-in working if you've just installed Maple 2015, or you've done a full uninstall and reinstall : http://www.mapleprimes.com/questions/209166-Excel-2010-And-Maple-17-Problem#comment224540 You can also use the old WinHelp file that comes with the Excel add-in as described.

Updating/installing a new Excel or updating Windows may cause problems for using the Excel add-in.

It's a good guess that the same approach will work for Maple 17 or Maple 18.

@tomleslie As far as I know, you need the 32-bit Maple installation, or at least some parts of it. You could experiment. The XLA file calls maple.dll in the bin.win folder, and probably also libmaplegmp-10.dll. I don't know what else.

So I was testing things in Maple 17 and Excel 2010 just because that's the setup I had left over from the last time I used the Excel add-in. I made some progress (got rid of the error I was getting) but ran into other problems (different errors).

Actually I'm using Maple 2015 and Excel 2016. Probably the multiple installations overwrote something, or the upgrade from Windows 7 to Windows 10 did.

I fixed the problem by completely uninstalling Maple 17 and Maple 2015, then deleting the add-in from the Excel add-in manager and deleting the Maple custom toolbar in Excel (right click on one of the Maple icons in Excel to get the delete option). Then I reinstalled Maple 2015, and installed the 32-bit add-in in both Excel 2010 and Excel 2016. No modification to the registry. So someone starting from a new installation shouldn't have problems, as long as they install the correct bit length version of the add-in, to match the bit length version of the Excel they're using. Some other messages I've seen suggest that upgrading Excel may cause problems, and certainly upgrading to a new Windows version may too.

Now the Maple help in Excel works, and the formula '=maple("x + x")' in a cell returns '2*x'. The Maple Function Wizard/Browser in Excel doesn't do anything - the browser opens but never populates with any function names.

From the Maple Help Browser in Excel, there is a button Using Maple in Excel. This is supposed to open a Windows help file which describes how to use Maple in Excel and how to use the toolbar icons. It uses a format no longer supported by Windows. Microsoft has released standalone executables to view these old help files, but has yet to release one for Windows 10. If you click the Using Maple in Excel button and get taken to a Windows error web page like this, it's because your Windows doesn't support the old help files and you need to install the standalone executable.

See:

• the links at the bottom of https://support.microsoft.com/en-gb/kb/917607
• http://www.komeil.com/blog/windows-help-program-winhelp-winhlp32-exe and
• for Windows 10, the answer to the question at http://answers.microsoft.com/en-us/windows/forum/windows_10-other_settings/winhlp32-for-windows-10/6cda96fb-0804-485c-85e2-008bed33265c

@Axel Vogt I've got things working, kind of, with the default locations for everything, which include spaces in the path names (e.g. ...\Program Files (x86)\...).

@tomleslie 

Thanks for the reply.

In your case, check whether your Excel 2010 is 32-bit or 64-bit. Since the error message is complaining about a missing WMIMPLEX but you've installed WMIMPLEX64.xla in the Excel Add-ins manager, it sounds like your Excel version is probably 32-bit. (The filename of the 32-bit version of the Maple add-in is WMIMPLEX.xla.)

The Maple Excel add-in documentation (from Maple help) is a little inaccurate from what I understand. They say to install the 64-bit version of the add-in if your Windows is 64-bit, and the 32-bit add-in if your Windows is 32-bit. But you can run 32-bit Excel on 64-bit Windows, and that setup has become very common since 64-bit machines are now standard. You need to match the bit length of your Excel version to the bit length of the Maple add-in. If your Excel is 32-bit, you'll need to install the 32-bit version of Maple 2015 to use the add-in.