Home > SQL Configuration, SQLServer, SQLServer 2005, SQLServer 2008, SQLServer 2008 R2, SQLServer 2012, Undocumented Functions > SQL Server – Identifying default data directory for multiple instances through registry

SQL Server – Identifying default data directory for multiple instances through registry

This is a follow up post from a comment on my blog.

Earlier I posted about using xp_instance_regread to get default data location for current instance. It translates a given registry path to instance specific registry path. This can return the value for a single instance only. However, if you need to locate default data directories for all available instances on a machine, you need to use xp_regread, which reads from an absolute registry path.

Registry path for default data location is same for different SQL Server versions:

HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\<InstanceName>\MSSQLServer


So the first thing we need before we can start reading data location from registry is list of instance name; these also can be read from registry using xp_instance_regenumvalues.

Registry path for instance name is as follows:

HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL

We need to retrieve these to a temporary structure so that we can use it further:

CREATE TABLE #tempInstanceNames


      InstanceName      NVARCHAR(100),

      RegPath           NVARCHAR(100),

      DefaultDataPath   NVARCHAR(MAX)



INSERT INTO #tempInstanceNames (InstanceName, RegPath)

EXEC   master..xp_instance_regenumvalues

       @rootkey = N'HKEY_LOCAL_MACHINE',

       @key     = N'SOFTWARE\\Microsoft\\Microsoft SQL Server\\Instance Names\\SQL'


SELECT      InstanceName, RegPath, DefaultDataPath

FROM        #tempInstanceNames

Result Set:

InstanceName  RegPath                    DefaultDataPath


DENALI3       MSSQL11.DENALI3            NULL

SQL08ENT      MSSQL10.SQL08ENT           NULL

SQL05EXP      MSSQL.1                    NULL

We have a list of instance names; now we need to iteratively read registry value for each path; and append it to DefaultDataPath. The paths we need to read from registry will be:

1. HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQLServer

2. HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL11.DENALI3\MSSQLServer

3. HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10.SQL08ENT\MSSQLServer

4. HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\MSSQLServer

These needs to be read using xp_regread. I have used dynamic SQL to iterate through the list:


SET         @SQL = 'DECLARE @returnValue NVARCHAR(100)'


'EXEC   master.dbo.xp_regread

@rootkey      = N''HKEY_LOCAL_MACHINE'',

@key          = N''SOFTWARE\Microsoft\Microsoft SQL Server\' + RegPath + '\MSSQLServer'',

@value_name   = N''DefaultData'',

@value        = @returnValue OUTPUT;


UPDATE #tempInstanceNames SET DefaultDataPath = @returnValue

WHERE RegPath = ''' + RegPath + '''' + CHAR(13) FROM #tempInstanceNames




SELECT      InstanceName, RegPath, DefaultDataPath

FROM        #tempInstanceNames

Result Set:

InstanceName         RegPath                    DefaultDataPath

MSSQLSERVER          MSSQL10_50.MSSQLSERVER     C:\Database\Data

DENALI3              MSSQL11.DENALI3            C:\Database\Denali\Data

SQL08ENT             MSSQL10.SQL08ENT           C:\Database\2008\Data

SQL05EXP             MSSQL.1                    C:\Database\2005\Data

I have updated the column in #tempInstanceNames so that it can be used further.

You can download the script from here.

Hope This Helps!


If you like this post, do like my Facebook Page -> SqlAndMe
EMail me your questions -> Vishal@SqlAndMe.com
Follow me on Twitter -> @SqlAndMe

  1. David
    January 5, 2012 at 11:11 pm

    Excellent post…thank you!

  2. February 14, 2012 at 4:59 am

    Thanks, I already downloaded the script and implemented it.

  3. Maa421S
    April 17, 2012 at 8:38 pm

    nice script, thanks

  4. Jim
    April 19, 2012 at 9:07 pm

    the scripts can’t be downloaded any more?

    • April 19, 2012 at 9:15 pm

      Sorry about that… could you please try now?

  5. July 26, 2012 at 12:16 pm

    the scripts can’t be downloaded any more?

    • August 29, 2012 at 7:33 pm

      The link is now fixed…

  6. Kevin Robinson
    September 26, 2012 at 11:36 pm

    Thanks for share this excellent post with us is really interesting, keep up the good work

  1. May 6, 2013 at 5:16 pm

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: