So I got Win 10 on the lappy and it seems fine, but my question is, if I put it on the desktop, which is my FS computer, how does FSX and all the add-ons interact with Win 10?

Anyone have any problems?

Whilst I'm not aware of any serious issues using FSX with Win10 I'm not a user myself; there's always a risk of compatibility problems (especially as FSX was made 9 years ago for Vista and XP) so I recommend staying with Win7.

It's also important to consider hardware drivers because older controllers may not work with Win10 (e.g. PFC have confirmed their stuff won't work in W10). I've not heard of any FSX performance improvements from using Win10, so it's potential pain for no gain (at least from a flight sim perspective). I know Microsoft is pushing it very hard but I've yet to be convinced myself.

FSX:SE and P3Dv3 are less likely to give headaches with Win10 as they are newer and still being maintained, although LM still recommends Win7.

EDIT: Just remembered that PMDG's 747-X is not compatible with Win10, although they are releasing a new one.

Yes, good advice Chris, thanks.

I'm quite happy with Win 7 on the FSX PC so no need to change.

Win 10 replaces 8.1 on the lappy and it's quite an improvement. (IMO)