if we lost windows password?

The is no such option to recover the password. You need to reinstall your operating system.

Reinstall the operating system.. insert the bootable operating system cd and instal it

You can recover the password, there are plenty of tools out there which will crack your password from the SAM Database(the database where windows store the password), Ophcrack(one of my fav. tool)is a free Windows password cracker based on rainbow tables, you can download it for free, burn it into the cd. First, Start your computer > Insert the Ophcrack cd > boot from the Ophcrack cd ,you can choose the various options provided by the Ophcrack i.e GUI or command line.

reinstall the os

Reinstall the operating system.

I guess it can be retrieved by the computer technicians. I had lost it once and they were able to restart and then I put in another pass word..

 

If your PC is on a domain, your system administrator must reset your Pass word.

For more details see this link

https://support.microsoft.com/en-us/help/14105/windows-8-what-to-do-if-forget-windows-password

 

 

Login your pc as administrator or in safe mode and create a new user profile