Win32::Registry - delete_value - system cannot find file specified

Ruby
1

Using: Windows 7 Pro SP1 x64

I’m trying to delete an existing value in my registry (verified
existence using regedit) with the following code:

require ‘win32/registry’

keyname = ‘SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate’
access = Win32::Registry::KEY_ALL_ACCESS

Win32::Registry::HKEY_LOCAL_MACHINE.open(keyname, access) do |reg|
reg.delete_value(‘SusClientId’)
end

the output of which yields the following exception:

C:/Ruby200/lib/ruby/2.0.0/win32/registry.rb:768:in delete_value': The system cannot find the file specified. (Win32::Registry::Error) from C:/main_script.rb:7:inblock in ’
from C:/Ruby200/lib/ruby/2.0.0/win32/registry.rb:389:in open' from C:/Ruby200/lib/ruby/2.0.0/win32/registry.rb:496:inopen’
from C:/main_script.rb:6:in `’

Could anyone help me with some insight? Thanks in advance