System with the Mpegport.sys driver repeatedly restarts after you install Windows XP Service Pack 2 or Windows XP Tablet PC Edition 2005

After you install Microsoft Windows XP Service Pack 2 (SP2) or Microsoft Windows XP Tablet PC Edition 2005, your computer repeatedly restarts. You do not receive an error message.

This problem occurs if all the following conditions are true:

• The system includes a legacy hardware DVD decoder that requires the Mpegport.sys driver.
• You installed the 32-bit version of Windows XP SP2 on a computer that supports hardware-enforced data execution prevention (DEP).

When you restart your computer, the Mpegport.sys driver tries to run from a memory location that is monitored by DEP. You receive a Stop error that is similar to the following:
Your computer may restart immediately if it is configured to automatically restart when a system failure occurs.

Contact the driver vendor for an updated version of the driver without the incompatibility problem. If an updated version of the driver is available, the driver can be installed in Safe Mode.

For additional information about Safe Mode in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:

To work around this problem, disable the Mpegport.sys driver in Device Manager by using Safe Mode. To do this, follow these steps:

1. Restart your computer.
2. Press the F8 key. On a computer that is configured to start multiple operating systems, press F8 when the Startup menu appears.
3. Use the arrow keys to select a Safe Mode option, and then press ENTER.
4. Click Start, click Run, type devmgmt.msc, and then click OK.
5. In the View menu, click Show hidden devices.
6. Expand Non-Plug and Play Drivers.
7. Right-click the Mpegport.sys driver, and then click Properties.
8. On the Driver tab, change the Startup Type to Disabled, and then click OK.
9. Restart your computer.

If you require the Mpegport.sys driver, you can also turn off DEP. To turn off DEP, follow these steps:

1. Restart your computer.
2. Press the F8 key. On a computer that is configured to start multiple operating systems, press F8 when the Startup menu appears.
3. Use the arrow keys to select a Safe Mode option, and then press ENTER.
4. Click Start, click Run, type cmd, and then click OK.
5. At the command prompt, type the following, and then press ENTER:
   bootcfg /raw “/noexecute=alwaysoff /fastdetect” /id 1
   If you have multiple start entries or start options, you may have to manually modify the Boot.ini file for your computer. To disable DEP by modifying the Boot.ini file, change the /noexecute policy level to alwaysoff.
6. Restart your computer.

This issue is known to occur if the Sigma Designs Hollywood Plus DVD decoder is installed on your computer.

For more information about data execution prevention, visit the following Microsoft Web site: The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.