When you are asking for this type of information you are probably doing something wrong.
When you set RequestExecutionLevel admin you are doing a machine/all users install and you should put your stuff under $ProgramFiles and HKLM.
If you need to do some per-user stuff then this should really happen the first time your application runs as that user (Copy template data from the install directory to $appdata etc) The "Active Setup" registry key can also be helpful...
IntOp $PostCount $PostCount + 1
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