Agree with xania Control panel, power options, what your power plan is, change plan settings, change advanced power settings, in the box that opens expand 'require a password on wake-up', change to no. If you've disabled sleep 'set to never' then the option to change will be greyed out.
Sorry guys, I didn't explain myself very well. What I meant to say was - Go to Settings/Accounts/Sign-in Options/Require Sign-in and set that box to "Never". It works. I can put my pc to sleep and wake it from sleep without having to sign in every time. It also boots straight to desktop from start-up.