Can anyone tell me why I can't access the registry key of "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData"?
if I query the GetSubKeysNames of "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer" it only returns one value being "Secure" ----> Where are all the other subkeys?
Thanks.
High odds that you are running your program on the 64-bit version of Windows and it is forced to run in 32-bit mode. The registry redirector will make you actually read the keys in HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node. And yes, that one also has a Microsoft\Windows\CurrentVersion\Installer key but it is pretty empty. Use Regedit.exe to compare.
The simplest fix is to remove the forcing. Project + Properties, Build tab, set the Target platform setting to AnyCPU. If you have VS2012 and up then untick the "Prefer 32-bit" option. Repeat for the Release configuration. If you must run in 32-bit mode then you can use the .NET 4+ RegistryKey.OpenBaseKey() method, passing RegistryView.Registry64.
来源：https://stackoverflow.com/questions/19769018/accessing-hkey-local-machine-software-microsoft-windows-currentversion-installer