RegDBQueryKey cannot list keys for 32- and 64-bit keys at the same time

Question

I have been facing a problem in InstallScript to get the list of registry keys for 32- and 64-bit installations.

My machine is Windows Server 2008 64-bit. I can install the SQL Server 2008 32-bit version or 64-bit version on this machine.

Now during the setup I need to know whether either of the SQL Server versions are installed.

As per my understanding,

• 64-bit applications on 64-bit machine are stored in Software\\Microsoft\\Windows\\CurrentVersion\\Uninstall.
• 32-bit applications on 64-bit machine are stored in Software\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall.

I have written a function which should search both these locations for SQL Server installation using the RegDBQueryKey function.

Even if I pass "Software\\Microsoft\\Windows\\CurrentVersion\\Uninstall" to RegDBQueryKey, it lists the keys of Software\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall.

Can anyone help me with this issue?

Answer 1

Set this flag before your call to RegDBQueryKey:

REGDB_OPTIONS = REGDB_OPTION_WOW64_64KEY;

That will disable the default forwarding to the 64-bit version of the key, and give you the 32-bit version. It applies globally, so when you're done make sure to reset the flag using:

REGDB_OPTIONS = REGDB_OPTION_USE_DEFAULT_OPTIONS;