Prevent sleep, hibernate, standby when your PC seems idle, with Econap
Econap is a light free tool that will help you make sure your PC won’t enter standby or any similar mode when it seems idle although you perform a task such as a download.
The interface of Econap is not something to be excited, but it’s easy to understand and use, although not as simple as you may suppose judging from its purpose.
Besides preventing standby indefinitely, Econap provides a stopwatch that would put your PC to sleep at a time you can decide. You can select certain conditions that would activate standby such as specific CPU use, etc.
Whatever criteria you may define for standby activation, you can always have particular processes ignore these and keep your PC awake.