The below are the files you need as an Enterprise user. If your company runs our Express version of Skype for Business, you'll need to follow this guide.
Choose the Skype for Business installation you wish to download.
Microsoft Skype for Business for Windows (last updated 20 November 2017)
Use these files to install the client - previous versions of the install software is no longer active. You don't have to reinstall the client on machines already running a previous version, however - these will still work.
If you don't know whether your computer runs 32 or 64 bit operating system, you can click the Windows button, search for System and click System in the section Control Panel.
Type will be listed in the section System.
Microsoft Skype for Business for Mac