Hi,
 I'm trying to install SD on a new desktop PC using windows 10.

I understand that I need to install .NET Framework 2.0 SP2 but when I use your installer I have to choose between
_x86.exe
_ia64.exe
_x64.exe

So which one do I need to install and do I also need to install KB959209?

it depends what type of chip your computer has ..... x86 is for older 32 bit computers, x64 is 'standard' 64 bit computers, and ia64 is for Itanium Architecture.   
It will probably be x64 that you need..... but to be sure, go to the Start button, and type "About your PC" .... which should then bring up the System window ..... about 8 lines down it will say something like "System type: 64 bit operating system, x64-based processor"

Many thanks. Yes its an i7 and its showing x64.
Do I still need to install KB959209?

Hi,
I don't think KB959209 is required on Windows 10 .... it's only for XP/ Vista.

Many thanks for your help