Hi, I am A. Stevens here to help with your question! Yes it is possible to upgrade your Windows 7 on Fusion 8 installation to Windows 10, though it is not as straightfoward as just updating it
A number of Fusion uses however are hitting an issue when trying to upgrade from Windows 7, 8 or 8.1.
During the “hardware validation check”, the VMware SVGA graphics driver is misrepresented as being incompatible. This is not true as the drivers have been signed by Microsoft and are indeed compatible with Windows 10.
The simple workaround is rather than using the upgrade method within the VM, download the .ISO and mount it to Fusion to perform the upgrade."
You can download the ISO here: https://www.microsoft.com/en-us/software-download/windows10