SBS 2008's sharepoint database log is 16GB, this client dont even use sharepoint

1> BACKUP LOG [SharePoint_Config_29c26fca-17b8-48c1-9704-b869932abcb6_log] WITH TRUNCATE_ONLY
2> Go
1> Use [SharePoint_Config_12345]
2> Go
1> DBCC SHRINKFILE([SharePoint_Config_12345_log],2)
2> Go
1> Exit

refer to http://msmvps.com/blogs/kwsupport/archive/2008/12/10/sbs-2008-and-sharepoint-log-file.aspx

and I quote here

If you are using the Windows internal database, if the sqlcmd command errors, try adding np: prior to the double backslashes. Like this:

sqlcmd –E –S np:\\.\pipe\MSSQL$MICROSOFT##SSEE\sql\query