Unless you have a specific reason to uninstall WLM and switch to some other email program, I suggest sticking with WLM. I used it for many months but have been using Microsoft Outlook 2007 for the last 6 months or so because I started using a Windows 8 laptop for email and I installed my full Office 2007 package (Word, Excel, etc.) on the laptop.
If you do switch to another email program, you can probably import the WLM messages. Most email software provides import capability.
I have been having a lot of problems with WLM and thought it best to reinstal.
However 2 days ago I installed thunderbird, and it copied all my emails over (well I think all of them) even tho I didnt request it. Both sites ask me to be the default, but I am still using wlm. Eventually I copied all my hotmail emails to a folder in another address, so I could attend to them later.
I'm not confident to back up and retrieve the msgs, if I knew thunderbird had ALL my emails, I would attempt the uninstal, and then re-instal
.. I have far too many emails to risk losing them as most are family history related.