Computer shuts down

Downloading large volume of email, left computer unattended while it did.
Came back, download complete, computer had turned off. Required turning power off to computer. then back on and restarting computer.
Started download of another program, again leaving computer unattended. Same results, same action.

Info:
Comp: HP dx5150 SFF
OP: Win 7 w/SP1

Sarge(

 

Your computer was sleeping. Open Control Panel from the Start Menu and click Power Options. Next to the selected power plan, click 'Change plan settings'. Change 'Put the computer to sleep' to Never.

Once you are more familiar with windows 7, you can create a Custom Power Plan.

 

Aaaaaaarghhh - cannot find such in control panel
Switched to Win 7 as XP not supported, opened Pandora's box-

 

You need to change the control panel view. Top right > Small Icons

 

Open Control Panel. Then look for Power Options - it's a green battery icon. Click it. The default power plans should be: Power saver, Balanced (recommended), and High performance. Click the radio button next to Balanced (recommended), and then click Change plan settings. The second item should be Put the computer to sleep. Change it to Never.

PS I know you are new to Windows 7 and will keep that in mind when answering future posts.

 

Finally found it, adjusted (I hope)