How to check for value of registry to check that it is not NULL

Usage and Config
1

(imported topic written by rkc91)

How to I create a relevance to check for a value of key in registry check that it is not NULL

eg exists value “abcdef” of key “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\ABDEFGHIK” of registry

there is value for abcdef

I need to check that for Null

2

(imported comment written by jessewk)

exists value “abcdef” whose (it != “”) of key “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\ABDEFGHIK” of registry

or maybe

exists value “abcdef” whose (exists it) of key “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\ABDEFGHIK” of registry