As standard, accounts come with support for one subdomain. You can upgrade this online if you require more. This section should hopefully cover how to create a subdomain in plesk.
Creating a subdomain
Once you are logged in to siteadmin, as outlined in this tutorial, then click the subdomains button.
To add a new subdomain, click the Add New Subdomain button.
Fill in the name of the subdomain, for example naming it forum would allow you to access it using http://forum.yourdomain.ext
(Please replace .ext with .com /.co.uk /.net etc)
If you plan on using our script installer site to install any scripts, you must set the subdomain to use it's own username and password, rather than sharing the main account details.
It is also advisable to ensure that PHP, CGI and mod_perl support are all enabled for the subdomain.
Click the OK button to finalise the creation of the subdomain. Please note that it may take up to 60 minutes for the subdomain to start working correctly.