|Two possible causes:|
1. The CMOS battery on the motherboard has expired and needs replacing, This is usually a silver coin-shaped battery like those used in electronic calculators etc.
2. The selected Internet Time server may not be sending time-signals to your PC.
You can try a different time server by clicking the clock at bottom-right.
Then click "Change date and time settings".
Click the tab labelled "Internet Time".
Click "Change Settings".