Compatibility Matrix

http://kb.act.com/app/answers/detail/a_id/29767/~/act%21-compatibility-matrix

98 ME NT 4.0 2000 XP Server 2003 Vista Server 2008 Server 2008 R2 Windows
7		 Windows
8 & 8.1		 Small
Business
Server
2011		 Server 2012 Server 2012 R2 Windows 10 Server 2016
ACT! 6
 X X X X X                      
ACT! 2005 (v7)
       X X X
(not Small Business Server)		                    
ACT! 2006 ( v8)
       X X X                    
ACT! 2007 (v9)
       X X X                    
ACT! 2008 (v10)
         X X X                  
ACT! 2009 (v11)
         X X X

X
(not Small Business Server)

                
ACT! 2010 (v12)
         X X X X1   X            
ACT! 2011(v13)
         X X X X1  

X

            
ACT! 2012 (v14)
         X X X X1   X            
ACT! 2013 (v15)
         X2 X X X1 X X X3 X3 X3      
Act! v16
         X2 X X X1 X X X X X      
Act! v17
         X2 X X X1 X X X X X X X  
Act! v18
         X2 X4 X4 X1 X X X X4 X X X  
Act! v19
                 X X X X4 X X X X5
Act! v20
                 X X X X4 X X X X
Act! v21
                 X X X 6 X X X X

 

1 Act! Premium (access via web) is not compatible with Server 2008 Small Business Server or Server 2008 Foundation edition.

2 Act! Premium for Web 2013 and above is not compatible with Windows XP.

3 Requires ACT! 2013 Service Pack 1.

4 Upgrade support only. Clean installs not supported.

5 Requires v19.2

6 Now incompatible due to .NET Framework update