To change the interface language for your customers, follow these steps:

1. Go to Home > Interface group title menu > Languages.
2. Select the interface language that will be set as default for new control panel users and click Make Default.

To change the interface skin for your customers, follow these steps:

1. Go to Home > Interface group title menu > Skins.
2. Select the interface skin (theme) that will be set as default for new control panel users and click Make Default.

To change the interface language and skin for your control panel, follow these steps:

1. Go to Home > Account group title menu > Interface Preferences.
2. Specify the following:
   1. Administrator's interface language. Select the language for your control panel.
   2. Administrator's interface skin. Select the skin (theme) for your control panel.
3. Click OK.

   Note that on that control panel screen, there are also the following settings, which you might want to review (we recommend leaving their default values for most users):

   1. Button label length. To prevent lengthy button captions in languages other than English from overlapping in the control panel, you may want to specify a limit here. Any button caption longer than the defined limit will be shortened and ended with ellipsis (...).
   2. Home page preset. Once you customize the Home page and save the settings in a template, you will be able to select your template here.
   3. Administrator's interface customization template. Once you customize the control panel and save the settings in a template as described in Using Interface Customization Templates, you will be able to select your template here.
   4. Allow multiple sessions under administrator's login. By default, Parallels Plesk Panel allows multiple simultaneous sessions for several users logged into the control panel using the same login and password combination. This can be useful when delegating management functions to other users or in case if you accidentally close your browser without logging out, thus becoming unable to log in again until your session expires. You may want to switch off this capability, if you do not need it.
   5. Prevent users from working with the control panel until interface screens are completely loaded. Leave this selected to avoid errors that might occur when users try to interact with control panel before is it ready.