Reason:
The database attached is read-only because the default startup account "Network Service" that starts SQL Server does not have sufficient permissions on the attached (Attach) database files.
Solution:
Open SQL Server Configuration Manager, click Local Use SQL Instance object, right-click Property-"Login-" Built-in account-"modified to" Local System "-" Confirm-"server automatically restart-" all OK
Refer to the document address: http://www.cnblogs.com/lin614/archive/2008/05/24/1206365.html
I have been accompanied by the resolution of this issue, and I have also received responses to other problems that have been encountered before.
The questions are as follows:
You cannot back up the database at the location you specify.
You cannot restore a database backup at a specified location.
Prompt error for "Device Management Open Error ...", now finally found the crux, in their own installation sql2005, select "Built-in account" for "network system" caused. In accordance with the above method to solve the OK.