Windows 8 Pro goes to Sleep after 60 Seconds of Inactivity
Export and Remove:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\238C9FA8-0AAD-41ED-83F4-97BE242C8F20\7bc4a2f9-d8fc-4469-b07b-33eb785aaca0\DefaultPowerSchemeValues
SOURCE: http://www.sevenforums.com/tutorials/35767-sleep-return-timeout-unattended-wake-up.html