There's a lot of factors that COULD be the problem, so let's try to isolate some of the more obvious ones.

Do you have an antivirus running? If so, is it in silent/gaming mode? Try right-clicking it and setting it to silent/gaming if it isn't.

Are you running Elona as an administrator in addition to win7 compatability? Try that.

Do you have two graphics cards? On various laptop computers, they'll have an integrated/awful card, and a dedicated/decent card. If you need help setting Elona to use your dedicated card, let me know.

Are the power settings on your computer set to high performance? If not, adjust them in the Power Settings option in the Control Panel.

Finally, Windows 10 doesn't play nice with a lot of sound/video cards. I expect that to get ironed out in a year or twenty, but if you've still got your Win7 install disc (if you got one with your previous computer...) lying around, it might not hurt to run a seperate partition for Windows 7...

If any of these seem confusing or you're not sure what to do, let me know. Hopefully we'll get to the bottom of it soon.

Other people might have more experience with Win10; I don't use it myself, so keep an eye open for othe replies, and let me know if any of mine result in a faster experience.