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Windows xp
Windows XP automatically resumes from standby or hibernation and then returns to standby or hibernation after two minutes?
The subject behaviour is expected if Wake-on-LAN configured.
To workaround this feature:
1. Right-click My Computer and press Properties.
2. Select the Hardware tab.
3. Press the Device Manager button.
4. Double-click Network Adapters.
5. Right-click your network adapter and press Properties.
6. Select the Power Management tab.
Click on the image below
7. Uncheck the box next to {Only allow management stations to bring then computer out of standby}
8. Uncheck the box next to {Allow this device to wake the computer}
8. Press OK and close the open Windows.
9. Then close all windows
10. Restart your computer