Verify that this problem occurs also without being connected to the internet by adjusting the time manually to 17:59, having WLAN disabled and any LAN cables unplugged if necessary.
If that did not fix your problem, ensure your laptop is free of viruses and stuff like that.
How old is the laptop you're having this problem on..?
To get to the end, if your Windows installation is on your device for some time already, backup any personal data, programs and porn to an extern drive and reinstall Windows on it again, format your hard drive (meaning "delete" anything and create a new volume if necessary) during this process and see if this issues persists. In this case, it would be very hard to help you out any further.