xp_dirtree
Get a list of folders under the named folder.
EXEC master..xp_dirtree 'F:\DATA'

xp_enum_oledb_providers
List all OLE DB providers available.
EXEC master..xp_enum_oledb_providers

sp_MSgetversion
To get the current MS SQL Server version.
EXEC master..sp_MSgetversion

xp_enumcodepages
List all code pages and character sets.
EXEC master..xp_enumcodepages

xp_enumerrorlogs
Returns a list of all error logs with their last change date.
EXEC master..xp_enumerrorlogs

xp_enumdsn
List all System DSNs and their descriptions.
EXEC master..xp_enumdsn

xp_readerrorlog
Returns the contents of the error log.
EXEC master..xp_readerrorlog

xp_fixeddrives
List all hard drives and available disk space in Mb.
EXEC master..xp_fixeddrives

xp_getnetname
Get host WINS name.
EXEC master..xp_getnetname

xp_enumgroups
Return a list of NT user groups and their description.
EXEC master..xp_enumgroups

xp_fileexist
Check to see if a file exists.
EXEC master..xp_fileexist 'F:\DATA\my.log'

xp_regdeletekey
Delete a registry key.
EXEC master..xp_regdeletekey
@rootkey='HKEY_LOCAL_MACHINE',
@key='SOFTWARE\Microsoft'

xp_regdeletevalue
Delete a registry key value.
EXEC master..xp_regdeletevalue
@rootkey='HKEY_LOCAL_MACHINE',
@key='SOFTWARE\Microsoft',
@value_name='MSSQL'

xp_regread
Read a registry key.
DECLARE @test varchar(20)
EXEC master..xp_regread @rootkey='HKEY_LOCAL_MACHINE',
@key='SOFTWARE\Microsoft',
@value_name='MSSQL',
@value=@test 80
SELECT @test

xp_regwrite
Write a registry key.
EXEC master..xp_regwrite
@rootkey='HKEY_LOCAL_MACHINE',
@key='SOFTWARE\Microsoft',
@value_name='MSSQL',
@type='REG_SZ',
@value='NEW'

To get your CD Key that you used to install SQL Server, check the following registry key using regedit:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\80\registration\CD_KEY

More often than not you may not have access to the local machine. Instead you can use xp_regread, this undocumented and not well known extended stored proceedure allows you to read contents from the Windows registry of the host. The syntax is:


EXECUTE xp_regread [@rootkey=]'rootkey',
[@key=]'key'
[, [@value_name=]'value_name']
[, [@value=]@value OUTPUT]


To view your CD Key run:


USE master
EXEC xp_regread 'HKEY_LOCAL_MACHINE',
'SOFTWARE\Microsoft\Microsoft SQL Server\80\registration',
'CD_KEY'


The SQL will return your CD install Key as a string.