Error message when you install SQL Server 2005 Express Edition Service Pack 1 in Windows Vista: "Windows NT user or group '<COMPUTERNAME>\SQLServer2005MSSQLUser$<COMPUTERNAME>$MSSQLSERVER' not found"

When you try to install Microsoft SQL Server 2005 Express Edition Service Pack 1 (SP1) on a computer that is running Windows Vista, you receive the following error message:

This problem occurs if the following conditions are true:

• The Windows Vista-based computer has a name that consists of lowercase characters or that consists of a mixture of lowercase characters and uppercase characters. For example, the computer name resembles Workstation-1.
• You specify a case-sensitive collation setting for the SQL Server service when you install SQL Server 2005 Express Edition SP1.

Windows Vista uses the following two methods to return the computer name in response to a request for the computer name:

• Windows Vista can return the computer name in uppercase characters.
• Windows Vista can return the computer name in the actual mixed case characters that appear in the System Properties dialog box.

During one part of the installation of SQL Server 2005 Express Edition, the Setup program requests the computer name as mixed characters. However, Windows Vista returns the computer name in uppercase characters instead. The Setup program also requests the computer name in other parts of the installation of SQL Server 2005 Express Edition. Windows Vista may then return the computer name in mixed case characters.

The SQL Server 2005 Express Edition Setup program compares the received computer names. Generally, this does not cause a problem because computer names are not case sensitive in Windows Vista. However, if a case-sensitive collating sequence is specified when you install SQL Server 2005 Express Edition, the result of the name comparison between the computer name in uppercase characters and the computer name in mixed case characters fails. Therefore, the installation of SQL Server 2005 Express Edition SP1 is unsuccessful.

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

Method 1: Change the computer name to use only uppercase characters

A computer name is not case sensitive in Windows. For example, Windows recognizes "Workstation-1" and "WORKSTATION-1" as the same computer name. To change the computer name, follow these steps:

1. Click Start
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   , right-click Computer, and then click Properties.
2. Under Computer name, domain, and workgroup settings, click Change settings.
   
   
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   If you are prompted for an administrator password or for a confirmation, type your password, or click Continue.
3. In the System Properties dialog box, click Change.
4. In the Computer name box, note the original computer name, and then type a temporary computer name in uppercase characters. For example, type WORK-TMP.
5. Click OK.
   
   Note If you are prompted to enter the name and password of a domain account that has permission to rename the computer, type your credentials, and then click OK.
6. When you are prompted to restart the computer to apply the changes, click OK, click Close, and then click Restart Now.
7. Follow steps 1 through 6 to change the computer name to the original computer name. When you specify the original computer name, type the name in uppercase characters. For example, type WORKSTATION-1 instead of Workstation-1.
8. Install SQL Server 2005 Express Edition SP1.

Method 2: Use a case-insensitive collation setting for the SQL Server service

When you install SQL Server 2005 Express Edition SP1, do not select a case-sensitive collation setting. For more information about how to select the collation setting when you install SQL Server 2005 Express Edition SP1, see the following Microsoft SQL Server 2005 Books Online topics:

For more information, click the following article number to view the article in the Microsoft Knowledge Base: