If by LR5 you mean the legacy standalone version that is obsolete and no longer supported. It may not even install on a new Windows computer. You need to consider subscribing to Adobe's Lightroom Classic to continue your current LR5 efforts seamlessly.
My preference for a Windows Laptop would be one of the Microsoft Surface laptops. These have a set of components that Microsoft has chosen to work well together and as such will not have the component conflicts that plague most windows machines.
For the same reasons, I would recommend an Apple Mac as these do not have the hardware performance problems that many Windows Users encounter.
Yes, it's the legacy version, which hasn't been supported for a while but isn't obsolete in the sense that it works as well as it did on Windows 7. However, my antivirus is not going to work with Windows 7 for much longer.
I wasn't persuaded by the Adobe subscription on cost grounds and then being a hostage to fortune for ever. It seems to be directed at professions who can recover costs. I wasn't really persuaded by freeware alternatives either.
I was thinking of Dell or HP as being the most solid. Interesting that you mention a Mac, which I like the idea of. I believe the screen quality is better than most Windows machines, although I thought compatibility would be more of an issue for most applications. I'll look into that and the Microsoft you mention. Thanks for your reply.