Hide administrator account from winlogon, still being able to use it.

Hello, I was unsure whether to open this thread in here or in Windows System Security, anyway, I'm configuring a laptop for a friend of mine, I've set up the windows with a standard administrator account (not the hidden one) and have just created a standard user account for him so he won't mess up and I can easily restore it if anything goes wrong. The problem is that now I'm not able to login automatically, instead being prompted for account choice: Admin or User.
I've tried to use the registry trick

Code:

In the Registry, you can create a list of accounts to hide at HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList. Create a REG_DWORD value named Administrator, with any data (0 is fine)

The problem is that when I wanted to login as Admin I couldn't because standard user can't set the DWORD back to 1 (visible) so I had to boot from DVD and load the registry hive and restore it from there.
Is there an easier way to get what I want, hide the Admin from Winlogon but still being able to switch to that account whenever I need it without using the DVD?

The problem is that it's 4 years that I'm not using Windows 7 after having switched to OSX and I find it a little messy or I've just forgot how to get it working as I need.

Thank you.

Log On Automatically at Startup

Put a password only you know on the real Administrator account.

But what if he wants to do something that needs UAC? He would need you to log in for him.