Windows Photo Viewer in Windows 10 is not color managed and so it will not appear the same as in Lightroom. You need to use color managed applications like IrfanView if you need to view your photos outside of Lightroom.Please read LightRoom Export Problem - edits and COLOR not accurate!!
I get the impression that the image does not display identically in Library and Develop.
If that's the case, you probably have a defective monitor profile.
As troubleshooting, and as a temporary solution, try setting the monitor profile to sRGB.
If this fixes the issue, you should calibrate your monitor with a hardware calibrator.