Hi Joan, and welcome to JustAnswer! My name is ***** ***** I'll be happy to help you today.
I did some research on this for you and apparently many people have reported the same problem, and long story short is that HP and NVIDIA are going to have to work together to get new drivers for that video card developed and released to their customers. Most people are saying that they simply have not gotten Windows 10 to work with their system at all and are waiting HP to release a fix for the problem.
However, there is one person that I ran across who said he was able to get Windows 10 installed by downloading the Win 10 ISO and installing it from a DVD. If you would like to try that, you can download the ISO from the following link:
And then once you've installed Windows 10, you can try to install the video card drivers:
64 bit: http://www.geforce.com/drivers/results/82758
32 bit: http://www.geforce.com/drivers/results/82701
What you would need to do is download the ISO and burn it AS AN IMAGE FILE, not as a data file, to a DVD. If you don't have experience working with ISOs and need some clarification on that, just ask me and I'll be happy to help with that.
Personally, I think it would be best just to stick with the version of Windows that you currently have until HP releases and official fix for the issue. A lot of people have reported problems after upgrading to Windows 10 as it is.
If you have any other questions on this, just respond back and I'll be happy to help you. And please remember to rate the answer at least 3 stars/OK Service so that I receive credit for assisting you.