I can set it manually or by Internet time sync but it does not keep time or update again from the Internet automatically.

Another real time wasting feature of Windows 8?  Gosh Microsoft, I really need to get some productive work done!

Does it get off sitting there running, or does it change when shut down?   If it's when it's off, I'd suspect the BIOS battery, otherwise just how much time difference are we talking about, and is it always the same, and could virtualization be involved?    

Hi, Mike:

Time settings between servers & clients on MS WINDOWS environment have always had serious problem of functionality that in my particular case, I solved using logon/logoff scripts applied by GPO. Approximate text I recommend having is:

echo off
NET TIME \\<DC SERVER> /SET /YES

More info at:

Using NET TIME for all Workstations and Servers
http://support.microsoft.com/kb/120944/en

Hi,

Meanwhile, you can also re-register time service in your Windows 8.1 system as a test

Open commmand prompt
In the Command window type net stop w32time
Type w32tm /unregister
Type w32tm /register
Type net start w32time

Check whether the time in your BIOS is correct.

If the Windows 8.1 and Windows 7 use different machines, and this issue only happened after you shut down your Windows 8.1 machine, then it might be the CMOS battery issue in your Windows 8.1 machine, you can consider to change a cmos battery.