Install a [NTP daemon for Windows][1] on both machines and set one of the daemons as a server and the other as a client, or set both as peers.

The NTP daemon can not only adjust its own computer's system time. Additionally, each daemon can be a client, server, or peer for other NTP daemons:

• As client it queries the reference time from one or more servers.
  
• As server it makes its own time available as reference time for other clients.
  
• As peer it compares its system time to other peers until all the peers finally agree about the "true" time to synchchronize to.

Have fun :) [1]: http://www.meinberg.de/english/sw/ntp.htm#ntp_nt_stable

Install a NTP daemon for Windows on both machines and set one of the daemons as a server and the other as a client, or set both as peers.

The NTP daemon can not only adjust its own computer's system time. Additionally, each daemon can be a client, server, or peer for other NTP daemons:

• As client it queries the reference time from one or more servers.
  
• As server it makes its own time available as reference time for other clients.
  
• As peer it compares its system time to other peers until all the peers finally agree about the "true" time to synchchronize to.

Have fun :)