无法读取C ++中的注册表项

Question

I have a registry entry I can't seem to read in C++, but it shows up in Regedit .

Using the following C++ snippet:

openResult=RegOpenKeyEx( HKEY_LOCAL_MACHINE, _TEXT("SOFTWARE\\Microsoft\\NET Framework Setup\\NDP\\v4\\Full"), 0, KEY_READ, &root);
readResult1=RegQueryValueEx(root, _TEXT("InstallPath"), NULL, NULL, data1, &size);
readResult2=RegQueryValueEx(root, _TEXT("fake_entry"), NULL, NULL, data2, &size);

I get Error 2, ERROR_FILE_NOT_FOUND for my second RegQueryValueEx() call.

As you can see in the image below, my fake_entry exists.

I created this entry via Regedit .

Microsoft's Registry Keys Affected by WOW64 does not include the location I'm trying to read, and as you can see in the picture below, my fake_entry is not in the Wow6432Node location.

• Yes, I understand this isn't a registry location I should be changing. I stumbled upon this as I was debugging my code and am curious why my added fake_entry doesn't work.
• Yes, I've read about Registry Redirector .
• Yes, I've read this question .
• Yes, I tried reading fake_entry at SOFTWARE\\\\Wow6432Node\\\\Microsoft\\\\NET Framework Setup\\\\NDP\\\\v4\\\\Full with the same error.

Running Windows 7, 64 bit, C++ in Visual Studio 2010, using ASCII character encoding.

Am I misunderstanding the Registry Redirector? Is there a problem with my code? Are there some sort of permission settings on certain portions of the Registry? I'm obviously missing something. Please point me in the right direction.

Answer 1

Try

openResult = RegOpenKeyEx( HKEY_LOCAL_MACHINE, _TEXT("SOFTWARE\\Microsoft\\NET Framework Setup\\NDP\\v4\\Full"), 0, KEY_READ|KEY_WOW64_64KEY, &root);

according to MSDN you should use either KEY_WOW64_64KEY or KEY_WOW64_32KEY for WOW64 access

Answer 2

You are misreading the table of keys affected by WOW64. From the very top of that page:

The following table lists registry keys that are redirected, shared by both 32-bit and 64-bit applications, or redirected and reflected on 64-bit Windows. Subkeys of the keys in this table inherit the parent key's behavior unless otherwise specified. If a key has no parent listed in this table, the key is shared.

The parent of your key is HKLM\\Software which is redirected. So your key is also redirected. It inherits that from its parent, as the documentation that I quoted explains.

You'll need to read the 64 bit view using KEY_WOW64_64KEY.