Note: Do not hack public computers as you may be prosecuted.. the following lesson is just for ethical hacking (defensive) and not for attack.
Sometimes it happens that you forget your windows password!!!
how to login now??
Step 1: Download the bootable image of Linux from here.
Step 2: Download the software to make a bootable usb drive like this one.
Step 3: make the usb pen drive bootable and install the .iso image we downloaded earlier.
Step 4: Reboot your system and select the bios option to set the boot sequence. Put the usb to first preference.
Step 5: if booted successfully, you will see a ophcrack startup page. click on "automatic". It will start with Linux OS.
Step 6: Just wait and see the password displayed on the screen.
If you want to prevent your computer from being hacked this way then follow the Defensive action given:
1. Use a long password more than 10 characters
2. Use combination of alphabets and numericals and symbols in password
3. Put a password for BIOS settings
4. Disable booting from pen drive (usb drives)