Acctivate is distributed with Microsoft SQL Server 2017 Express.
The Acctivate server installer also installs Microsoft SQL Server 2017 Express with a SQL Server Instance named "ACCTIVATE". While this version doesn't need to be purchased, even outside of Acctivate usage, SQL Server Express editions do have limitations. 2017 Express is notably limited to a 10GB database file size, 1410MB of memory (RAM) and also a single CPU socket. We typically recommend Companies that will have more than 10 concurrent Acctivate users to consider upgrading to a Standard version of Microsoft SQL Server.
With newer versions of SQL Server, you need to also consider the version of the operating system your server is running on. Windows Server 2008 and 2008 R2 and Windows 7 are not supported operating systems for newer versions of SQL Server. This means you need to consider either upgrading your operating system to a newer, recommended version of Windows or you need to consider installing Acctivate on a different server altogether.
If you have further questions regarding any of this, feel free to contact our Support Team. We are happy to answer any questions.