32bit and 64bit Property Handlers?

[fafalone]

My ShellBrowse project allows reading/writing the properties of anything with a registered property handler shell extension that can be loaded.

I've noticed that the vast majority of them work in both Explorer and my project. Explorer, and my Windows version (7), are 64bit, and obviously VB apps are 32bit. However, I went to add a new extension to handle FLAC files, and installed the 32bit version, with the hopes that it would work in both Explorer and my control... it does not. It works in my control, but in Explorer, it can't load properties and produces an 0x80004005 (Unspecified) error trying to write properties.

The only other one that's caused trouble is the 64bit MS Office 2013+ extension, which works in Explorer but not my app. Apart from these two, all others on my system work in both.

Can anyone clarify the circumstances under which a Property Handler shell extension can be used in both 64-bit Explorer and 32-bit VB?

[dilettante]

However, I went to add a new extension to handle FLAC files, and installed the 32bit version, with the hopes that it would work in both Explorer and my control... it does not. It works in my control, but in Explorer, it can't load properties and produces an 0x80004005 (Unspecified) error trying to write properties.

Well I suspect Explorer can only use a 64-bit handler in 64-bit Windows. Maybe uninstall the 32-bit one and then install the 64-bit one? Then try both applications.

I don't think you can install both, so maybe WOW64 will somehow manage the impedance mismatch? Or perhaps some extensions install with a 32-bit proxy registry entry allowing use from 32 bit programs? In that case it will depend on how professional the author/packager was.