For all of these tips you will need know the password to an administrator account. You can check whether an account is an administrator in the Accounts section of System Preferences.
1. Add a message to the login window
You can add a string of text above the list of users in the login window. To do this, start by opening up Terminal. This is located in the Utilities folder, inside the Applications folder. Once it has loaded, paste in the following line and press return:
sudo defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText "Hello There"
Replace “Hello There” with your text. To remove the text, type the following line:
sudo defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText ""
2. Hide accounts
If you find yourself with an overly long list of users in the login window or you just want to get rid of that annoying scroll bar down the side, you can stop accounts appearing in the login window.
Start by go to the Accounts pane in System Preferences, and find the “short name” of each user you want to hide. Once you have these, open up Terminal and enter the following:
sudo defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array-add shortname1 shortname2 shortname3
Replace shortname1 2 and 3 with the short names of the user accounts you wish to hide. You can hide as many as you like, just separate each with a space.
To make a hidden name appear again, type the command with no names in it, therefore resetting the list of hidden users.
sudo defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array-add
Notice that doing this adds an extra option to your login window – “Other…” When you select this, you will be presented with text boxes to enter a username and password.
If you aren’t running OS X 10.4, this doesn’t work. Another option is to replace the list of users with username and password text boxes. Go to the Accounts pane in System Preferences and click on Login Options. There you will find an option to display the login window as name and password fields. This isn’t as pretty, but saves time if you have lots of users, and is also more secure.
3. Change the Apple logo
You can replace the large Apple logo that appears at the top of the login window with any tiff image that is 90×90 pixels. In the Finder, choose Go to Folder from the Go menu or press Command-Shift-G. In the dialog box that appears, type the following line:
A folder called Resources should appear. Here you will find an image called applelogo.tif. You will need to create a copy of this file, just in case you ever want to revert back to it. The easiest way to do this is to hold the Option key and drag it to a safe place (like your Documents folder). Now, rename you new image “applelogo.tif” and drag it to the Resources folder to replace the old file. You will be asked to type in an administrator password.
To change back to the Apple Logo, just drag the copy that you made back to the Resources folder.
4. Get useful system stats
The name of you Mac is displayed in the login window below the words “Mac OS X”. Since Mac OS X 10.4.3, you can click on the name of your Mac to show different statistics about your machine. Each time you click, it will cycle through different bits of information that are particularly useful when troubleshooting problems.
The order of the statistics are as follows:
One click: Your OS X version number (e.g. Version 10.4.9)
Two clicks: Your OS X build number (e.g. Build 7M271)
Three clicks: Your mac’s serial number (e.g. WN1511LHKNW)
Four clicks: Your mac’s IP address (e.g. 220.127.116.11)
Five clicks: The status of any networked account
Six clicks: The date and time (e.g. Saturday, January 20 2007 4:02:31 AM GMT)
Seven clicks: Back to where you started, the name of your computer.
So you click a few times and set the information line to your favourite thing, but next time you log in, it has changed back to the name of your mac. To change the bit of information that appears first, you need to do a bit of tinkering in the Terminal (Applications/Utilities). Open Terminal and type the following command:
sudo defaults write /Library/Preferences/com.apple.loginwindow AdminHostInfo HostName
Depending on which piece of information you want displayed, replace HostName with one of the following:
After doing this, hit return, and the next time you view your login window the information you chose will be displayed. To change it back to normal, simply repeat the command with
HostName at the end.
5. Change the background image
There are ways to change the background image by replacing the Aqua Blue image, but that is slightly crude. A better way to do it is using the Terminal. Type the following command and press return:
sudo defaults write /Library/Preferences/com.apple.loginwindow DesktopPicture /Users/Shared/mynewbackground.jpg
The last part,
/Users/Shared/mynewbackground.jpg is the location of the image you want to use. You don’t have to type it out. Just paste the command as far as
DesktopPicture and put a space after it. Then find your image in the Finder, and drag it onto the Terminal window. The address to your image should just appear. As far as I can tell, you have to place the image in a place that all users have access to (the shared folder is a good place).
To change back to the normal Aqua Blue image, type the following command and press return:
sudo defaults write /Library/Preferences/com.apple.loginwindow DesktopPicture /Library/Desktop\ Pictures/Aqua\ Blue.jpg