If you’re already tied to a particular platform, you should stick with the one you already use. Neither Mac or Windows is necessarily better for editing photos and both have access to the most popular apps and services. For example, Lightroom, one of the most widely used services for editing photos, is available on Mac and Windows. In the rare situation when there is an app exclusively on one platform, you can likely find an alternative for the other platform that’s just as good. Personally, I would recommend an Apple laptop. Not only has the company worked to optimize the hardware and software of its newest machines, but if there’s an Apple Store nearby, you can make an appointment to get it fixed—something that's harder to do if you own a Windows laptop.