All the Pentium-D CPUs certainly support Windows 10 - is there a specific "feature" that has you curious?
As far as LGA775 CPUs in general go, the only feature in Windows 10 (or Windows 8.x) that is NOT supported is Hyper-V (due to lack of Extended Processor Table support in any CPU in LGA775).
I migrated from LGA775 (Q6600) to LGA1150 (G3258), and Hyper-V was one noticeable gain in terms of OS features (the G3258 supports EPT - Q6600 didn't).
There certainly are other CPU-specific reasons (or even LGA-specific reasons) to upgrade; however, that depends on what you want to leverage.
Many thanks for your posting.
The reason I raised this query is that I currently run Windows 7 Pro 64 bit on the processor without any problems - so assumed that it would be ok for Windows 10.
However, when I ran Microsoft's Get Windows 10 upgrade app it told me that the PC was unable to run Windows 10 because the cpu wasn't supported.
I did a bit of checking around and found a couple of references to bugs in the Get Windows 10 app that might give rise to this message.
These suggested checking that Windows Update KB2952664 is installed - which it is; and, also, references to VT-x and NX support - and the spec on the Pentium D 830 suggests that this processor doesn't have this feature.
That made me wonder if this processor doesn't, in fact, support Windows 7.
Ideally, I'd like the option to be able to upgrade to Windows 10 64 bit using the present hardware - Intel Pentium D 830 in an Intel D945GNT system board with LGA775 socket.
Sometime, I plan to upgrade the hardware but, just at the moment, I'd like to avoid the upheaval, as I guess it would involve replacing processor, system board, memory and mouse (this latter because current system boards no longer seem to have two PS/2 inputs on them - and I need one for my original IBM M series keyboard).. Doing that and migrating all the software and data would be a fairly time-consuming operation which I'd like to put off for a while, if I can.
I'd be interested in any information or suggestions.