If you are trying to update to a Windows Insider Preview build, you may encounter an update compatibility hold and receive the message, "This PC can't be upgraded to Windows 10: Your PC has a driver or service that isn't ready for this version of Windows 10. No action is needed. Windows Update will offer this version of windows 10 automatically once the issue has been resolved."
This issue was resolved and the safeguard hold has been removed. Please note, it can take up to 48 hours before you can update to a new Windows Insider Preview build.