How do I unlock my Dell computer without password.?

If you don't have the Windows password you will need to reinstall the operating system. Windows XP is obsolete however and its reinstallation is not recommended.

What si the model of the Dell so we can determine Windows 10 compatibility?

Windows Vista is obsolete. Its time for you to install Windows 10 Insider 64 Bit Built 10030:

http://dellwindowsreinstallationguide.com/download-microsoft-windows-and-office/download-microsoft-windows/download-windows-10-technical-preview-iso/

Use it as a stepping to get Windows 10 RTM. Microsoft's representative Gabriel Aul has stated that Microsoft will not cut Windows 10 Insiders off from reaching Windows 10 RTM.

Your question is very suspicious. It's easy to doubt the source of this computer,why did its former owner forget his password?but my dad forgot his administrator's password on his computer (He has a bad memory, Lololololo.........) Reinstall a clean system.

To unlock a computer without password,that would take brute force.Only in this way can the user bypass the password input request two login computer.

Show you this:https://www.winpwd.com/

This post is over five years old and hasn't been set to "resolved". I recently had the same problem when my mother asked me to unlock her previous old Dell laptop, but she had completely forgotten the password to it.

I found this guide today and followed its first method and successfully unlocked my Dell computer. I hope it will be useful for you as well.

@Philip_Y

ip​ 

Dell windows XP T7570

Products key :BVHF4-VXRD4-BHTPH-8VQDT-3B83T

@Nyandemohisblessed​siasahr

Dell inspiron 15

300 series