我的数据库显示为只读。False(databae->rightclik->property-option->database Readonly=>false所以我在单击确定按钮后将数据库只读属性更改为）出现一些错误：
Alter failed for Database 'Vallett'.
Unable to open the physical file "C:\Program Files (x86)\Microsoft SQL Server\MSSQL.1\MSSQL\Backup\Vallett.mdf". Operating system error 5: "5(Access is denied.)".
Unable to open the physical file "C:\Program Files (x86)\Microsoft SQL Server\MSSQL.1\MSSQL\Backup\Vallett_1.ldf". Operating system error 5: "5(Access is denied.)".
Database 'Vallett' cannot be opened due to inaccessible files or insufficient memory or disk space. See the SQL Server errorlog for details.
ALTER DATABASE statement failed. (Microsoft SQL Server, Error: 5120)