See here:
System requirements for Symantec Endpoint Protection 12.1.6 MP1, MP1a, MP2, MP3, MP4, MP5
Operating system (Desktop)
- Windows XP (32-bit, SP3; 64-bit, SP2; all editions except Starter and Home; all patches applied, including Internet Explorer)
- Windows 7 (32-bit, 64-bit, RTM and SP1; all editions except Starter and Home)
- Windows 8 (32-bit, 64-bit)
- Windows 8.1 (32-bit, 64-bit)
- Windows 8.1 update for April 2014 (32-bit, 64-bit)
- Windows 8.1 update for August 2014 (32-bit, 64-bit)
Operating system (Server)
Note: Windows Server Core edition is not supported. Windows Server Core does not include Internet Explorer, which Symantec Endpoint Protection Manager requires to work.
- Windows Server 2003 (32-bit, 64-bit, R2, SP1 or later; all patches applied, including Internet Explorer)
- Windows Small Business Server 2003 (32-bit; all patches applied, including Internet Explorer)
- Windows Server 2008 (32-bit, 64-bit, R2, RTM, SP1, and SP2)
- Windows Small Business Server 2008 (64-bit)
- Windows Essential Business Server 2008 (64-bit)
- Windows Small Business Server 2011 (64-bit)
- Windows Server 2012
- Windows Server 2012 R2
- Windows Server 2012 R2 update for April 2014
- Windows Server 2012 R2 update for August 2014