VS 2008 Getting Subkeys From The Registry?

VB.NET Private gpo_office_hklm As String = "SOFTWAREPoliciesMicrosoftOffice12.0OutlookSecurity"
Private gpo_winupdate_hklm As String = "SOFTWAREPoliciesMicrosoftWindowsWindowsUpdateAU"
Private gpo_activedesktop_hklm As String = "SOFTWAREMicrosoftWindowsCurrentVersionPoliciesActiveDesktop"
Private gpo_explorer_hklm As String = "SOFTWAREMicrosoftWindowsCurrentVersionPoliciesExplorer"
Private gpo_system_hklm As String = "SOFTWAREMicrosoftWindowsCurrentVersionPoliciesSystem"
Private Sub EnumerateKeysHKLM(ByVal lvw As ListView)

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Normally, that exception is thrown when an object's value is Nothing. However, I've been through each subkey manually and everyone has a name. The only one I could think of that doesn't, are the (Default) keys.

The issue is that I can't seem to figure out how to loop through the subkeys and check if they're nothing. If I create a loop and call ".GetSubKeyNames() to check if they're Nothing, I still get the exception because it attempts to get the names before I can even check them.