Check Out How is MS SQL Server Error 5171 Resolved?

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MS SQL Server is the ultimate solution for users to store their database. It keeps their data secure or safe from unknown entity. Oversize database also provided by SQL Server to the users without any limitations imposed on it. But due to some causes like Virus and other infections on the system, not properly shutdown the system, forget to attach few files, server crash, hardware & software failure, corrupted data, and so on. The following reasons are responsible for creating MS SQL Server error 5171.

Sometimes, users might face such situations they have tried to resolve it using some oriented methods. But when they have attached their .mdf files of SQL Server database an error will display such as "MDF is not a primary database file" which creates an SQL error 5171. In the following section, we will discuss more consequences, cause behind the occurrence of an error and a way to overcome such issue.

  • Consequenses of Error
  • Reasons of Error
  • Solution to Fix Error

Consequences of MS SQL server Error 5171

While working on the system, if a user might encounter several outcomes including login failure of SQL server, enable to restore SQL database files then there are several common indications that is involved in the occurrence of such error. Additionally, users enable to create 'tempdb' database and might face difficulty during attaching the database files to the server.

Error Description

The sample of MDF is not a primary database file error 5171:

C:\ProgramFiles\MicrosoftSQLServer\MSSQL10_50.MSSQLSERVER\MSSQL\db.mdf is not a primary database file.

ms sql server error 5171

Reasons behind "SQL Error 5171"

The commonly faced '.mdf is not a primary database file error 5171' can arise due to several issues. Which may be related to the internal configuration files or general file related issues. The major reasons for encountering this MS SQL Server error 5171 may include:

  • Crashed Index:

    While users want to read their data, due to damaged index users cannot able to view their files easily.

  • Corrupted header File:

    MDF file header, which contains crucial database information like file signature, the size of the file, compatibility etc. Original data is stored on the rest of pages. In the case of header page, that is not recognized by SQL server, the entire .MDF files are not considered as valid.

  • Virus infection:

    When multiple files running on SQL server at a time the system will be infected with viruses. It will become more complex for users to operate their desktop.

  • Hardware Failure:

    Users want to store some data while downloading due to insufficient space/hardware fail users can not able to save necessary files.

  • Human faults:

    Sometimes SQL server becomes fail while login the page due to enter the incorrect ID. Users forget to attach the files properly.

Generally, .mdf is not a primary database file microsoft sql server error 5171 is fixed due to these issues happened. However, if the issue persists, then it means that there is some critical issue with user's system. This problem needs to be fixed with manual tricks and users are recommended to take help from technical experts to fix the problem.

Solution to fix SQL Database Error 5171

In the below section we are discussing the repair utility to overcome this MS SQL Server error 5171 issue. That can safely restore the corrupted index, table and procedures while accessing the SQL database. Users are capable of repair MDF file and NDF files of SQL database. With the help of this solutions, the user can easily remove this bug. However, if the error as resulted in any crashed to the database, that can be repaired with the help of repairing utility solution. There is one resolution to rectify MDF is not a primary database file error 5171 of SQL Server, are mentioned below:

A user allows to fix this issue using individual file attachment process that allows to attach single file gradually to the database or even a user can also try to execute sp_attach_single_db stored procedure to overcome this above issue.


These days, SQL server is most widely used to maintain the database among users. However, while users try to access the database files then, users face a SQL database error 5171 i.e. .mdf is not a primary database file that has mentioned above. The symptoms and reasons of error are discussed. Also gives the manual solution to fix "MS SQL Server Error 5171".

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