Cant login on my dell laptop

Hello Ali B;

What version of Windows are you using?
You can try a System Restore.

Yes. You can try booting in safe boot (press f8 on boot) and then system restore. You can also try pressing ctrl alt delete when it has booted to just wallpaper screen to see what programs are running in background and try shutting them down one by one to see if one of these is causing the problem. Lastly, although it may sound weird, in my experience sometimes having a flash drive in one of your usb sockets or a cd/dvd in the drive can sometimes stop windows from booting fully.

^+1 finn

Note: You don't have to completely restore your system, you can just restore it to an earlier date so you won't lose any personal files/settings. Is there anything you've done recently (e.g. torrents, new installations, etc.) that could have possibly disrupted anything?

finn - is that your system with the 3 monitors???