How to perform a clean boot procedure to start a Windows Vista-based computer or a Microsoft Windows XP-based computer. When you use a clean boot procedure to start a computer, Microsoft Windows starts only basic devices and services when it starts.

When you start Windows by using a regular startup, several programs start automatically and run in the background. These programs may include third-party antivirus programs and system utility programs. These programs may interfere when you install, run, or use a game or program such as Microsoft Flight Simulator or Microsoft Streets and Trips. If this occurs, you can use a clean boot procedure to prevent these programs from starting automatically. You must be logged on as an administrator or as a member of the Administrators group to complete a clean boot procedure. If the computer is connected to a network, the network policy settings may also prevent you from completing the clean boot procedure.

For Windows Vista-based computer

Method 1: How to perform a clean boot procedure on a Windows Vista-based computer
Note: You may experience a temporary loss of some services functionality when you follow these steps. When you restore the settings, the functionality will be restored. However, the original error message or behavior may return.

1. Click Start, type msconfig in the Start Search box, and then press ENTER.
   If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
2. On the General tab, click Selective Startup.
3. Under Selective Startup, click to clear the Load Startup Items check box.
4. Click the Services tab, click to select the Hide All Microsoft Services check box, and then click Disable All.
5. Click OK, and then click Restart.

After the computer starts, test the game and see whether the problems occur. If the problem does not occur, continue to Method 3 to determine what is causing the problem.

For Windows XP-based computer

Method 2: How to perform a clean boot procedure on a Windows XP-based computer
Note: You may experience a temporary loss of some services functionality when you follow these steps. When you restore the settings, the functionality will be restored. However, the original error message or behavior may return.

1. Click Start, click Run, type msconfig in the Open box, and then click OK.
2. On the General tab, click Selective Startup.
3. Under Selective Startup, click to clear the following check boxes:
• Process SYSTEM.INI File
• Process WIN.INI File
• Load Startup Items
4. Click the Services tab, click to select the Hide All Microsoft Services check box, and then click Disable All.
5. Click OK, and then click Restart.

After the computer starts, test your game and see whether the problems occur. If the problem does not occur, continue to Method 3 to determine what is causing the problem.

Method 3: Determine what is causing the problem

Step 1: Start the System Configuration Utility

Windows Vista
To start the System Configuration Utility in Windows Vista, click Start in the Start Search box, type msconfig, and then press ENTER.

If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.

Windows XP
To start the System Configuration Utility in Windows XP, click Start, click Run, type msconfig in the Open box, and then click OK.

Step 2: Enable half the Services items
a. Click the Services tab, click to select the Hide All Microsoft Services check box.
b. Click to select half of the check boxes in the Services list.
c. Click OK, and then click Restart.

Step 3: Determine whether the problem returns
a. Start the game.
b. If this problem occurs, repeat step 1 and step 2. In step 2.b. click to clear half of the check boxes that you originally selected in the Services list.
c. If this problem does not occur, repeat step 1 and step 2. In step 2.b. select only half of the remaining check boxes that are cleared in the Services list. Keep doing this until you have selected all the check boxes.
d. If only one service is selected in the Services list, and you experience this problem, the service that is selected in the list is the service that is causing the problem. Go to step 6.
e. If you find that the items in the Services list are not causing this problem, go to step 4.

Step 4: Enable half of the Startup items
a. Repeat step 1.
b. Click the Startup tab, and then click to select half of the check boxes in the Startup list.
c. Click OK, and then click Restart.

Step 5: Determine whether the problem returns
a. Start the game.
b. If this problem occurs, repeat step 1 and step 4. In step 4.b., click to clear half of the check boxes that you originally selected in the Startup list.
c. If this problem does not occur, repeat step 1 and step 4. In step 4.b., select only half of the remaining check boxes that are cleared in the Startup list. Keep doing this until you have selected all the check boxes.
d. If only one service is set in the Startup list, and this problem occurs, the service that is set in the list is the service that is causing the problem. Go to step 6.
e. If you find that the items in the Services list are not causing this problem, see the "Similar solutions" section.

Step 6: Resolve the problem

After you determine the specific program or service that causes the behavior, contact the program manufacturer to determine whether the issue can be resolved. Or, you can run the System Configuration Utility with the offending program or service unchecked on the list.

Original Microsoft Article