Windows 8 issue

Im converting a file from my softwear onto disc and coz i leave the laptop to get on with the job and when i get back to the laptop its gone into like a sleep. I then have to right click the desktop and entre my password to find out that my converting to disc was dead.. when i stop at the laptop converting this never happens...is there a way to stop my laptop from doing this?
Thank you.

Control Panel > Power Options. You can adjust on of the existing power plans or create a custom one. I have a custom one to do the following when I don't want power options to bug me.

Thank you

You are very welcome.