I found this in a few different places around the 'net - hopefully it's helpful:
How to Change the Length of Time That Your Computer Is Inactive Before Your Status Becomes "Away"
This article describes the "Away" status in Windows Messenger. This article also describes how to change the length of time that elapses before your individual status appears as "Away" in Windows Messenger.
The "Away" status appears automatically after your computer has been inactive for a period of time that is equal to the Wait time for your screen saver.
To manually specify "Away" as a status:
- Click File, click My Status, and then click Away.
To change the length of inactive time before your status becomes "Away,":
- Either change the screen saver Wait setting in the Windows Display Properties dialog box.
- or, if you want to specify a time other than the screen saver Wait time, change the inactivity time in the Windows Messenger Options dialog box.
To change the Windows screen saver Wait setting:
- Right-click the Windows Desktop, and then click Properties.
- Click the Screen Saver tab, and then type the appropriate number of minutes in the Wait box. (You must have a screen saver selected.)
- Click Apply.
The screen saver Wait time automatically appears in the Windows Messenger Options dialog box as the default "Away" status wait time.
To select an "Away" status wait time that is different from your screen saver Wait time:
- In Windows Messenger, on the Tools menu, click Options.
- Click the Preferences tab.
- In the Show me as "Away" when I'm inactive for box, type the number of minutes. This number overrides the screen saver setting and is the time that elapses before Away appears next to your name on the list.