I'm using Windows 10 on both systems.
Perhaps the version is the issue. I downloaded the latest version (5.7 I think?) The icon on my PC says 5.4.
Please click on the below link to download Lightroom 5 on your computer.
Once downloaded, please click on the below link to update Lightroom to version 5.7.1
Let me know if this helps.
This worked. Thank you very much!