It’s very easy to find the installed date and time of windows xp / 7 / vista Os in your computer. It is not provided as an information in system informations or else but is very easy to findout. To do this, You have to open the Windows os and go to start -> run -> Type in “cmd”. the comand editor will show up.
Now type in systeminfo in the command editor
Now wait for some time for the information to be loaded. After everything is successfully loaded, You will get a screen of information as shown below. There are many information displayed about your pc including the install date, system time, last boot .. etc
Out of this, the original install date gives you the correct date and time of your windows operating system installation