I had used both the phones, but I would probably go with the android. I would like you to consider this points over windows:-
1) Android is more customization options
2) It is easy to use even for a non tech person
3) It provides most of the apps for free and tons of apps that are useful for work, even windows apps like, MS Word, Excel, etc
4) It supports almost all applications in the market right now, also it gets the latest updates easily
One thing I would like to mention is that, Windows had stopped manufacturing windows phone and also gave a statement that they will no further be providing updates to the windows phone sold.