Registry.CurrentUser is null

I am using the following property to set/read registry v开发者_JS百科alues in my code. However, in the line:

RegistryKey regKey = Registry.CurrentUser;

regKey is null. This is happening only in a few machines. Any idea?

RegistryKey regRPP = Registry.CurrentUser.CreateSubKey(@"Software\Softech\FaceReader");

//this is the path it will create

regRPP.SetValue("FaceReaderURL", "http://localhost/pnm/v4_spp/");