Dev preview

[SJBirdy]

I have an old lumia 920 and would like to put the developers preview of windows phone 8.1 on it, i have see a few reviews saying you can sign up to be a windows developer for free but everytime i try it wants to charge me and ideas?

 

[Silviu Bogusevschi]

All you need to know about the Windows Phone 8.1 'Preview for Developers' | Windows Phone Central
Check this article, it should not charge you anything.