Ok, now I have time :P
At cmd type: net stop w32time
Modify this key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags, under Value data, type 5, and then click OK.
Then: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer\Enable NTPServer type 1 under Value data, and then click OK.
Then cmd: net start w32time
Now, on client / server side (NOT THE MASTER!) do the following:
right click on your clock, change:
At the top there are 3 tabs, select INTERNET TIME, then CHANGE SETTINGS and finally type the IP or name on the dropdown list.
Done.