Installing MySQL on Windows

By Michael J. Ross
2008-02-28


MySQL Already Installed?

Before you start installing a brand new instance of MySQL, you should first determine whether or not you already have an earlier version of it installed, and if so, what to do about the older installation and any databases created using it. First, look in all of the directories where you have installed applications in the past. For Windows, "C:\Program Files" is the default installation directory. It is possible to have multiple versions of MySQL installed, usually in different directories whose names contain the version numbers.

If you find an old version of MySQL installed on your PC, you have some options. Installing the latest version of MySQL over the older one has the advantage that you do not need to re-create any of those existing databases, as long as the formats of the database files are unchanged between versions. But it has the disadvantage of being a "dirty" install, which might not go as smoothly as a clean install into a new directory. For example, it can cause the MySQL Setup Wizard to see your old password (in the "mysql" database), making it impossible to apply the security settings, because you cannot login as root, even using the old password. More on this error, number 1045, later in the tutorial.

Clean installs may involve more work, but they are usually recommended. An additional benefit is that you can be sure that any problems discovered are not the result of leftover files from the old version.

Regardless of which option you choose, you should back up any databases that you want to save. The "data" subdirectory contains subdirectories for all the databases in the instance; but ignore "mysql" and "test", which are created and used by MySQL. To back up each database, use the mysqldump utility or a similar program, to export it in SQL format, so you can easily import it into the new instance. You may wish to copy the databases to a separate partition, or even hard drive, to be extra safe. Even though databases are rarely lost during installations, there is no point in running the risk.

MySQL runs in the background, as a Windows service. So next check what Windows services are installed and running on your system. Go to Start > Settings > Control Panel > Administrative Tools > Services, then click the Standard tab.

The third entry in the illustration above shows that MySQL is currently running, with the status of "Started". You do not need to manually stop the service before uninstalling MySQL, because the uninstallation process handles that automatically.

In this tutorial, we will assume that only a single instance of MySQL was previously installed. To uninstall it, go to Start > Settings > Control Panel > Add or Remove Programs. Click on the MySQL entry in the list, and then click the "Remove" button.

Tutorial Pages:
» Introduction
» MySQL Already Installed?
» Downloading MySQL
» Installing MySQL
» Configuring MySQL
» Verifying MySQL
» More Resources

Related Tutorials: » Implementing High Availability in MySQL » Stored Procedures are EVIL » MySQL Database Handling in PHP » A Flexible Method of Storing Control Data » Exploring MySQL CURDATE and NOW. The Same But Different. » Creating a PostgreSQL and MySQL driver