We just got WindowsXP with Vista and it came with 2 accounts -- both of them set as the Administrator. Of course, I changed one of the accounts to "limited", set the other as the administrator and gave each passwords. Problem? I can access them both but the Administrative one will not allow me to make any changes. (I can not even access "system restore.") What I need to do? I need to change the limited one to Administrative but cannot do so in the Administrative? Can anyone help me?

To make Windows Vista admin account act like XP On Windows Vista Business, Enterprise or Ultimate:
1. Click Start, type secpol.msc in the search box, then press Enter
2. From the list to the left, choose Local Policies, then Security Options
3. Set Accounts: Administrator account status to Enabled
4. Set User Account Control: Admin Approval Mode for the Built-in Administrator account to Disabled
â On Windows Vista Home Basic or Home Premium:
1. Click Start, type cmd in the search box, right click on the program cmd.exe and select Run as Administrator
2. In the command prompt window, type net users Administrator /active:yes then press Enter, you should receive a confirmation saying; The command completed successfully
3. Click Start, type regedit in the search box, then press Enter
4. Navigate to the section: [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
Double click FilterAdministratorToken and set it to 0
5. Next, logoff and you will see a new Administrator account is available. Login to this new Administrator account
Your now logged in to Windows Vista with full administrative rights.
You will not receive any security prompts like before and you should
have complete administrative rights to your machine.

Deep inside the bowels of Windows vista, there's a secret Administrator account, and it's different from the normal administrator account you most likely have set up on your PC. This Administrator account is not part of the Administrator group. (Confused yet? You should be.) It's a kind of superadministrator, akin to the root account in Unix, and by default it's turned off and hidden. (In describing this hack, we'll always use the capital "A" for the secret Administrator account, and a lowercase "a" for a normal administrator account.)
In versions of Windows before Windows Vista, the Administrator account wasn't hidden, and many people used it as their main or only account. This Administrator account had full rights over the computer.
In Windows Vista, Microsoft changed that. In VISTA , the Administrator account is not subject to UAC, but normal administrator accounts are. So the Administrator can make any changes to the systemand will see no UAC prompts.
Turning on the Administrator account is straightforward. First, open an elevated command prompt by typing cmd into the Search box on the Start menu, right-clicking the command prompt icon that appears at the top of the Start menu, then selecting Run as administrator — or just use the shortcut you created in the previous hack.
Then enter this command and press Enter:
Net user administrator /active:yes
From now on, the Administrator account will appear as an option on the Welcome screen, along with any user accounts you may have set up. Use it like any other account. Be aware that it won't have a password yet, so it's a good idea to set a password for it.
If you want to disable the account and hide it, enter this command at an elevated command prompt and press Enter:
Net user administrator /active:no
HOPE THIS HELPS.
:-)