This error may not be fixable given the computer processor has no integrated graphics chip, and GeForce 510Ti support for DirectX 11 depends on whether installing the latest driver, available here, for the GeForce 510 works.
I don't think it is a Windows problem, more of a problem that you have no hardware support for Direct X 11.1 and the lack of updated drivers for your graphics card due to support being dropped for that generation of graphics cards.
The card would still have the same generation graphics chip in it, just different firmware disabling some cores and processes. Hence the lack of up to date drivers for it and inability to use Direct X 11.1. It stops at Direct X 11.
No, in the specs section of VPX 13 and I think all versions that have used a version of the Infusion engine, the requirement for Direct X 11 has been stipulated but we see a lot of people on the forums that run into trouble if their systems are not supporting Direct X 11.1 or higher. All it does say is some functionality may be impaired if the system does not meet the minimum requirements (read that as all requirements when looking at specifications) and should preferably exceed them, and your system does not have an inboard Intel graphics chip which may also be a contributing factor as John suggests or the nvidia card without the additional driver updates is now missing an ability it should have.
That may be a point worth asking with Magix themselves.
510 or 560Ti the drivers are the same - there is a difference the 560Ti will work with DirectX 12 however it is restricted to the level 11.0 features only.