You cannot select the Upgrade option when you try to install Windows Vista, and you receive an error message: "Your upgrade partition has multiple operating systems"

When you try to install Windows Vista, you cannot select the Upgrade option. Also, you receive the following error message in the Install Windows dialog box:

NoteYou may find it easier to follow the steps if you print this article first.

To resolve this problem, follow these steps:

1. Start the computer, and then edit the Boot.ini file to remove any references to another operating system.
2. Remove any folders that contain files for other operating systems.

Edit the Boot.ini file

Warning If you edit the Boot.ini file incorrectly, you may be unable to start the computer.

Step 1: Save a backup copy of the Boot.ini file

1. Click Start, click Run, type sysdm.cpl, and then click OK.
2. In the System Properties dialog box, click the Advanced tab.
3. In the Startup and Recovery area, click Settings.
4. In the System Startup area, click Edit.
   
   The Boot.ini file opens in Notepad.
5. In Notepad, click the File menu, and then click Save As.
6. In the File name box, type Boot.bak, and then click Save.
   
   A backup copy of the Boot.ini file is saved to the top folder of drive C.

Step 2: Determine your version of Windows

1. Click Start, click Run, type Winver.exe in the Open box, and then click OK.
2. Note the version of Windows that appears at the top of the About Windows dialog box. For example, "Microsoft Windows XP Professional" may appear.
3. Click OK.

Step 3: Edit the Boot.ini file

1. If the Boot.ini file is not open in Notepad, follow steps a through d in step 1.
2. In the Boot.ini file, remove the lines that refer to operating systems other than the operating system that the computer is now running.
   
   Note After you remove these lines, you cannot start the computer by using these operating systems.
   
   For example, the Boot.ini file may include the following lines:

   [boot loader] 
   timeout=30 
   default=multi(0)disk(0)rdisk(0)partition(1)\WINXP
   [operating systems] 
   multi(0)disk(0)rdisk(0)partition(1)\WINXP="Windows XP <Version>" /fastdetect 
   multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows 2000 <Version>" /fastdetect 
   

   Note In an actual Boot.ini file, a version number appears instead of "<Version>."
   
   Remove any line that does not refer to the operating system that you noted in step 2c. For example, if the computer is running Windows XP Professional Edition, remove the following line:

    
   multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows 2000<Version>" /fastdetect 
   

3. In the File menu, click Save to save the new version of the Boot.ini file, and then exit Notepad.
4. Click OK two times to close the System Properties dialog box.

For more information about the Boot.ini file, click the following article number to view the article in the Microsoft Knowledge Base:

Back up and remove folders that contain files for other operating systems

To successfully install Windows Vista, you must also remove any folders that contain files of other operating systems. If any important files are stored in these folders, back up the folders first. For example, back up the folders to a CD or to an external drive. Or, move the folders to another partition on the same physical drive. For example, move the folders from drive C to drive D.

The folder that contains an operating system's files appears in the Boot.ini file. For example, in step 3, the folder that contains the files for Microsoft Windows 2000 is the WINDOWS folder.