confusion in sdk and vs 2012 fof windows phone

Question

pls tell me the difference b/w sdk 8 and vs 2012 for windows phone.....pls

Yash Nayak · Answer

Windows Phone SDK is a complete set of tools which you will require to make a Windows Phone application. If Visual Studio 2012 or later is already installed on your computer SDK installer will just add up the necessary components to VS to make it ready for WP development. That's it. Twitter: @YashTam

sachin patil · Answer

thanks for solving my previous doubts bt now im in big trouble ..im making an app on vs2k12 windows phone bt suddenly it stop working and showing this msg A required certificate is not within its validity period when verifying against the current system clock or the timestamp in the signed file. now what shoud i do for resolve this error pls pls pls pls help me out..