C# reads wrong registry data on 64-bit OS

Question

I\'m working on a 64-bit Windows and my applicaiton runs with elevated privileges. I have a problem with the following very simple piece of code:

myKey = Reg         


        

Answer 1

This is a duplicate of another article. Here is some information that should help.

How to read the 64 bit registry from a 32 bit application or vice versa

Answer 2

This is by design, 32-bit programs have a different view of the registry than 64-bit programs. They are redirected to the HKLM\Software\Wow6432Node key when they try to read a value from the HKLM\Software hive. If you build your C# program with Project + Properties, Build tab, Platform Target = Any CPU then it will run as a 64-bit program and won't get redirected.

32-bit programs can cancel the redirection but that's not easily done with the .NET RegistryKey class. P/Invoking RegOpenKeyEx with the KEY_WOW64_64KEY option is required. More info is available in this Windows SDK article.

---

EDIT: this is now also available to .NET with the .NET 4 specific RegistryKey.OpenBaseKey() method. Pass RegistryView.Registry64 to view the registry the way a 64-bit process would.

Answer 3

While i was running into same issue or same focus of the reason for this issue, I found a solution.

Use this:

//To set the Base to the right path set RegistryView to DEFAULT, Registry64 or Registry32 regarding the path you need. If you want to go over the x64 root:

RegistryKey rk = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64)
        .OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Run");

Now it'll behave the way you want.

Have fun!