SQL Server 2005 and SQL Server Express 2005 on The Same Machine
Installing both SQL Server 2005 (SQL) and SQL Server Express 2005 (Express) on the same machine can present a problem that might not be easily identifiable.
You can install both of these products on the same machine, though you must take care when choosing which options get installed. If you install the Management Tools for Express you will be unable to install the Management Tool for SQL.
So, if you have Express installed then want to install SQL, make sure you do not have Management Tools for Express already installed, otherwise none of the tools will be installed for SQL, and you'll be left with the likes of sqlcmd.exe for managing SQL untill the Express tools are uninstalled.
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