Running Multiple MySQL Instances on Windows For the following instructions, suppose that you want to run the  mysqld  server from two different versions of MySQL that are installed at  C:\mysql-5.7.9  and  C:\mysql-8.0.25 , respectively. (This might be the case if you are running 5.7.9 as your production server, but also want to conduct tests using 8.0.25.) To install MySQL as a Windows service, use the  --install  or  --install-manual  option. For information about these options, see Section 2.3.4.8, “Starting MySQL as a Windows Service” . Based on the preceding information, you have several ways to set up multiple services. The following instructions describe some examples. Before trying any of them, shut down and remove any existing MySQL services. Install the services as follows, using the full server path names to ensure that Windows registers the correct executable program for each service: To start the services, use the services manager, or  NET START  or  SC START  with the appropriate service names: To stop the services, use the services manager, or use  NET STOP  or  SC STOP  with the appropriate service names: With this approach, to specify options for the 5.7.9  mysqld , create a file  C:\my-opts1.cnf  that looks like this: • Approach 2:  Specify options for each server in separate files and use  --defaults-file  when you install the services to tell each server what file to use. In this case, each file should list options using a [mysqld]  group. • Approach 1:  Specify the options for all services in one of the standard option files. To do this, use a different service name for each server. Suppose that you want to run the 5.7.9  mysqld  using the service name of  mysqld1  and the 8.0.25  mysqld  using the service name  mysqld2 . In this case, you can use the  [mysqld1]  group for 5.7.9 and the  [mysqld2]  group for 8.0.25. For example, you can set up  C: \my.cnf  like this: # options for mysqld1 service [mysqld1] basedir = C:/mysql-5.7.9 port = 3307 enable-named-pipe socket = mypipe1 # options for mysqld2 service [mysqld2] basedir = C:/mysql-8.0.25 port = 3308 enable-named-pipe socket = mypipe2 C:\>  C:\mysql-5.7.9\bin\mysqld --install mysqld1 C:\>  C:\mysql-8.0.25\bin\mysqld --install mysqld2 C:\>  SC START mysqld1 C:\>  SC START mysqld2 C:\>  SC STOP mysqld1 C:\>  SC STOP mysqld2 [mysqld] basedir = C:/mysql-5.7.9 port = 3307 enable-named-pipe socket = mypipe1 1150