1. Commands and scripts added to Post-Setup
(Before logon) run under SYSTEM.
File / Add your batch file, and if you need to provide optional parameters, then copy them to the Parameters field.
HKCU refers to the currently logged on user's profile, and that doesn't apply to you from (Before logon).
2. Commands and scripts added to Post-Setup
(After logon) run with Admin rights.
Because they're executed after you're logged on, HKCU now applies to your user profile. File / Add your reg file to have it applied to the primary user's account.
3. If you need to apply reg changes for all new users, then you need to load Default User's NTUSER.DAT in (Before logon). Apply all reg changes
relative to the hive's temporary mount point, and then unload the NTUSER.DAT.
Code:
reg load HKU\TEMP "%SystemDrive%\Users\Default\NTUSER.DAT"
reg add "HKU\TEMP\Control Panel\International" /v sDecimal /t REG_SZ /d "." /f
reg add "HKU\TEMP\Control Panel\International" /v sLongDate /t REG_SZ /d "yyyy-MM-dd" /f
reg add "HKU\TEMP\Control Panel\International" /v sShortDate /t REG_SZ /d "yyyy-MM-dd" /f
reg unload HKU\TEMP