While I don't suggest it, as it wastes battery life, there is a way to do that. Go to the power settings, found by right clicking on the desktop, properties, and in one of those tabs, I can't remember which and I'm not on my computer right now, there should be something about power settings. Click that, and it will pop up a new window. In there, it will list all the settings. Change it to never standby and never hibernate. Also, if you have a screensaver, change it so that it doesn't go back to the Welcome screen when it goes off the screensaver.