32bit to 64bit upgrade in Office 365

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32bit to 64bit upgrade in Office 365
Office 365 Word 32 bit 
Tim Kempster




Posts: 47
 Joined: 2015-01-08
Dear Support

Quick question. Microsoft are apparently pushing an Office 365 update where Word is upgraded from 32 bit to 64 bit version if installed on a 64 bit Windows machine as an update.

If a user has an add-in installed built with add-in express will there be a problem here? Will the add-in continue to load OK or if at install time has the add-in been set to be the 32 bit version in some way?

I do know that add-in express add-ins are both 32 bit and 64 bit compatible but I'm not sure if this is accomplished at load time or install time of the add-in. In other words would upgrading Word underneath break the install of the add-in?

Regards

Tim
Posted 29 Aug, 2019 08:51:51 Top
Andrei Smolin


Add-in Express team


Posts: 17493
 Joined: 2006-05-11
Hello Tim,

When you install the add-in, adxregistrator.exe registers it for 32bit and 64bit Office versions; this is why your installer deploys both adxloader.dll and adxloader64.dll.

If the add-in assembly is built for the Any CPU platform, it will work with no problem.

A problem may occur if the add-in reads/writes to the registry: switching Office from 32bit to 64bit will cause the add-in to use the 64bit registry while data will be left in the 32bit registry.

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 29 Aug, 2019 09:06:08 Top
Tim Kempster




Posts: 47
 Joined: 2015-01-08
Good to know thanks. So as long as all reg access for settings etc. is to HKCU we the add-in should survive an update of the underlying host application (in our case Windword.exe) from 32bit to 64 bit.
Posted 29 Aug, 2019 09:23:00 Top
Andrei Smolin


Add-in Express team


Posts: 17493
 Joined: 2006-05-11
You are safe ONLY if your add-in does NOT store any data in the registry! Otherwise, you may need to write some code to retrieve that data from the registry of another bitness.

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 29 Aug, 2019 09:33:36 Top
Tim Kempster




Posts: 47
 Joined: 2015-01-08
I don't think that is right because HKEY_CURRENT_USER is agnostic to 32bit/64bit so it is safe to write there as I posted before?
Posted 29 Aug, 2019 09:37:49 Top
Andrei Smolin


Add-in Express team


Posts: 17493
 Joined: 2006-05-11
See https://stackoverflow.com/questions/8216472/why-cant-i-properly-read-32bit-registry-values-in-hkcu-on-64bit-machine. They needed to use Microsoft.Win32.OpenBaseKey to specify whether to open the 64 or 32-bit portion of the registry.

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 29 Aug, 2019 09:59:35 Top
Tim Kempster




Posts: 47
 Joined: 2015-01-08
No HKCU is shared in .Net as per the microsoft documentation referenced in the link you posted above:-

https://docs.microsoft.com/en-us/windows/win32/winprog64/shared-registry-keys

Anyway doesn't matter. The point is that the add-in will load ok if the base host app is changed from 32bit to 64bit.
Posted 29 Aug, 2019 10:06:50 Top
Andrei Smolin


Add-in Express team


Posts: 17493
 Joined: 2006-05-11
Okay. I might misunderstand something.

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 29 Aug, 2019 10:22:10 Top