SecureDoc 6.5 SR3 and above supports Windows 10 Home, Pro and Enterprise editions
Current Limitations of 6.5SR3 with Windows 10 (will be resolved in 7.1)
Upgrading to Windows 10 with FFE enabled is not supported
RMCE (Removable Media Container ) may fail to un-mount under Windows 10 environment

Using SDCredential Provider with Windows 10 can occasionally present SecureDoc logon screen
Workaround: User will need to select Cancel and logon with Windows credentials

Windows 10 may fail to come out of Hibernation on BIOS Legacy mode
For other Windows 10 editions listed below, we will be investigate support when they become available:
Windows 10 Mobile
Windows 10 Enterprise Mobile
Windows 10 IoT Core
More details on the different Windows 10 editions can be found at the links below:
IMPORTANT: Information for OS in-place upgrade
In place upgrade to Windows 10 is supported. If you are upgrading from an earlier versions of Windows (Windows 7 SP1 or Windows 8/8.1) to Windows 10 with SecureDoc installed, please refer to the following KB article 1442 "How to upgrade Windows 7 SP1 or Windows 8/8.1 to Windows 10 with SecureDoc 6.5 SR3 installed" for detailed information as additional specific steps are required.
Referencing: CRM KB: https://knowledgebase.winmagic.com/article.php?id=497