Batch file requests privileges

Greetings, I have a batch file created under the administrator account. The file is in the registry to "runonce". For a user with no password, the batch file runs fine. For a user with a password, the batch file requests the user's password that is logged on. Any idea why this happens? I would have expected the batch to run without needing the password of the user that is currently logged in.

The permissions are System and Administrators have full control, and users have 'Read and Execute' and 'Read'. The ID in question is a standard user. Thanks

Update: I gave users 'Full Control' of the batch script, and the UAC still pops up requesting a password.

it deletes a registry key in HKLU

Yes, HKCU, I always do that . I create the key in the administrator account, then Sysprep. Sysprep copies the profile, along with the registry key that points to a batch file to delete another registry key that gets created incorrectly during the profile copying. I know it seems a round about way to do this, but it works for the time being. The Regedit brings up the UAC for any account you login using a password.

Found another way to do it. Just add the registry entry in the sysprep setup xml file like so:
<FirstLogonCommands>
<SynchronousCommand wcm:action="add">
<CommandLine>REG ADD HKLM\Software\microsoft\windows\currentversion\runonce /v IUB /t Reg_SZ /d C:\mycommand.bat</CommandLine>
<Order>1</Order>
<RequiresUserInput>false</RequiresUserInput>
</SynchronousCommand>
</FirstLogonCommands>