Erm, if your using Windows 7 change sleep to hibernate. Will cease all power, but will resume as normal when you hit any key on the keyboard:
1. Start
2. Type "power options"
3. Choose "Balanced"
4. Click "Change Plan Settings"
5. Change Put Computer To Sleep as "Never"
6. Click on "Change Advanced Power Settings"
7. New windows appears
8. Open "Sleep"
9. Change "Sleep After" to NEVER
10. Change "Hibernate After" to your desired time
11. Hit Apply
12. Hit OK
Done!
Also, change what the power button does on your keyboard to make it go into Hibernate mode:
1. Click Start
2. Right click on Shut Down
3. Go to properties
4. Choose Sleep
5. Hit Apply
6. Then OK.
Done!
Hope this helps
As to the noise, thats just the pc ticking over in sleep mode. Nothing to worry about. Doing what I have stated above will sort out any problems.
Thanks