Installing for all users

By default, all COM registration data goes to HKEY_CURRENT_USER, making it user specific. This can be a bit of a problem if you want everything to be available to all users of the machine. It can be an even bigger problem if some of the users don't have enough access privileges to install things themselves.

One way this is resolved is through the ALLUSERS property in the Windows installer. This property allows COM registration data to be placed in HKEY_LOCAL_MACHINE which applies to all users. The ALLUSERS property can, of course, be baked into the installer from the beginning. However, it can also be supplied after the fact on the command line.

For example, with the .exe merge module wrapper supplied in the SDK you can do the following:
"Plantronics Device.exe" /VALLUSERS=2

The /V switch just passes through to MSIEXEC so it is the same as:
msiexec /i "Plantronics Device.msi" ALLUSERS=2

Setting ALLUSERS to 2 will attempt to install for all users, but will fall back to a per-user install if that fails. Setting ALLUSERS to 1 instead, will attempt to install for all users but then exit with an error if that fails.

More information about the ALLUSERS property can be found here.