How do I search for special characters (e.g. %) in SQL Server?

Use the Sql bracket ([ ]) or forward slash (\) when used with the special character.

Eg:

SELECT columns FROM table WHERE
    column LIKE '%[%]%' 

[or]

SELECT columns FROM table WHERE
    column LIKE '%\%%' ESCAPE '\

How to escape the square bracket itself

SELECT columns FROM table WHERE
    column LIKE '%[[]SQL Server Driver]%' 

 [or]

SELECT columns FROM table WHERE
    column LIKE '%\[SQL Server Driver]%' ESCAPE '\'

Source: 

http://sqlserver2000.databases.aspfaq.com/how-do-i-search-for-special-characters-e-g-in-sql-server.html