Mostly I use my laptop which has Windows Mail. I've set it to 'Leave messages on Server', but they aren't on my desktop's Windows Live Mail.
What should I be looking for to solve this?
You have to use the same email client for both computers ie Windows Live Mail on both . When you access your emails on either one they will download to that computer that you are using at the time.
You have to use the same email client for both computers ie Windows Live Mail on both . When you access your emails on either one they will download to that computer that you are using at the time.