After you install Windows Messenger 5.0, Windows stops responding, and the Csrss.exe process consumes 100 percent CPU usage

You may experience all the following symptoms after you install Microsoft Windows Messenger 5.0:

• Windows performs very slowly or stops responding (hangs).
• If you view the Processes tab in Windows Task Manager, you notice that the Csrss.exe process uses 100 percent of CPU usage and about 200 megabytes (MB) of memory.
• If you end the Msmsgs.exe process, or if you restart Windows, this problem is temporarily resolved.
• This problem occurs about 14 days or more after you either restart Windows or restart Windows Messenger if you do not restart one of them during that time.

This problem occurs because of a bug in the Windows Messenger Service Quality Monitor (SQM) data collection timer functionality. When new timers are started for SQM data collection, the previous timers are not ended. After about 14 days, about 32,000 timers may be created. This causes increased CPU usage and increased memory usage in Windows.

To resolve this problem download and install the latest version of Windows Messenger. To obtain the latest version of Windows Messenger, visit the following Microsoft Web site:

To work around this problem, use one of the following methods.

Method 1: Restart Windows Messenger

Use one of the following methods every 14 days:

• Restart Windows Messenger.
• Restart Windows.

Method 2: Disable Windows Messenger

If you do not use Windows Messenger, configure Windows Messenger so that it no longer starts automatically when you start Windows. To do this, follow these steps:

1. Right-click the Windows Messenger icon in the notification area, and then click Open.
2. On the Tools menu, click Options.
3. Click the Preferences tab, click to clear the Run this program when Windows starts check box, and then click OK.
4. On the File menu, click Close.
5. Right-click the Windows Messenger icon in the notification area, and then click Exit.

Microsoft has confirmed that this is a problem in Microsoft Windows Messenger 5.0. This problem was corrected in Microsoft Windows Messenger 5.0.482.