Applicable To:
SQL Server 2008 R2
SQL Server 2012
SQL Server 2014
Recently tried to change a SQL Server service account details from Local System to a domain account as per best practices.
When I went to change the service account details I encountered the below issue:

Solution:
Grant the new SQL Server service account Full Control on the following folders:
C:\Program Files\Microsoft SQL Server\MSSQL.MSSQLServer\MSSQL\
C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys\
And grant full control to the registry key:
HKeyLocalMachine\System\CurrentControlSet\Services\WinSock2\Parameters