Why does my Windows 7 machine accidentally turn on?

Three things to check..

1. Disable Wake-on LAN options in your BIOS. If they don't exist (i.e. HP machines), then you're OK.

2. Verify that you've turned off "wake timers".

http://www.neubreed.com.au/blog/2010/03/does_your_windows_7_wake_itself

1. Control Panel -> System and Security -> Power Options
2. Then click "Change plan settings" for your currently selected plan
3. Click "Change advanced power settings"
4. Scroll down to "Sleep" and expand the menu tree
5. Expand "Allow wake timers"
6. Click the word "enable" then drop-down and select "Disable" on both options if not already disabled
7. Finally Click "OK"

Disabling "Allow wake timers" helped me get a better night sleep ... I hope it helps you!

Disable wake timers

3. http://www.windows7hacker.com/index.php/2009/12/how-to-fix-windows-7-waking-up-after-putting-into-sleep/

How Do I fix the problem ?

To fix the problem go to Control Panel > Network and Internet > Network Connections

You should see your local area connection

Go to properties

Then go to Configure … (be sure to have the right one highlighted)

Now under the Power Management MAKE SURE uncheck “Allow this device to wake the computer” and it’s sub option

And you should make it looks something like this, and you should be good to go.

No more frustration find your computer being awake and knowing that you have put it into sleep.