Jeet Bhat,

Try the steps below to resolve the boot error.

Press F2 at powerup, go into setup and turn secure boot OFF.  That should let you boot the system.

 If the above does not work then, try the steps below.

Operating System Loader Has No Signature . . .

these steps resolved my issue:

1. On Startup, press F12

2. Reset Bios to default settings

3. Restart laptop

4. In Bios, select Boot Sequence menu

5. Manually ADD additional line with the name "Windows Boot Manager"

6. Select /EFI/BOOT/BOOTX64.EFI

7. Exit

Jeet Bhatt,

Did you try restoring the bios to default settings?

Click the link below to watch the Dell Video for systems stuck at the Dell Logo.

Laptop Stuck at Dell Logo

I follow ur steps...

but still same problem... system stuck in DELL logo screen.

If you're seeing this error and you don't know why, i.e. you didn't just install a fresh copy of an OS that doesn't support Secure Boot, then it means your bootloader is either damaged or has been compromised by malware.  If you disable Secure Boot and your OS still works, it's highly likely that you have been infected with malware, in which case you should either restore your PC from a known good full system backup if you have one, or else wipe your system and reinstall Windows from scratch.  You should not consider just disabling Secure Boot as a long-term solution.

@DELL-Jesse L, the error that the boot loader signature wasn't found in the Secure Boot database doesn't mean that the bootloader wasn't found at all; it means it failed the security check, so manually adding a boot entry won't help.  But more importantly, if you're going to advise users who have this issue to disable Secure Boot, you should emphasize that that should only be performed as a temporary diagnostic measure unless they have a good reason for turning it off, e.g. running an old version of Windows or some version of Linux that doesn't support Secure Boot.  Telling people who have this issue to just turn off Secure Boot is equivalent to telling someone whose smoke detectors went off to just remove the batteries from the smoke detector.

I agree about workarounds, but then why would any malicious object do this? There is no profit or other gains in disabling a persons' computer. 20 years or so ago this sort of behaviour was rife, but these days it is more about financial gain and stopping a laptop booting gains nothing!

Just a thought.

@UKTrev  Because not all systems have UEFI Secure Boot enabled, and the ones that don't will NOT be prevented from booting after they're infected.  And even among people with Secure Boot enabled, some of them who get infected and end up with an unbootable system will see bad advice on the Internet to just disable Secure Boot as a workaround to get their system booting again, and the ones who do that will now be infected and still have a running system.  And lastly, some people just like to wreak havoc even if they don't profit from it.

Not really difficult to see the motivation if you think about it.

Worked for me, with a couple of things to add,

As previously mentioned by another contributor, it is actually \ instead of / so should read:  \EFI\BOOT\BOOTX64.EFI

But for me I changed in BIOS to boot from legacy mode which got me into Windows and using Dell Update I updated the BIOS.

I was then able to go into BIOS on reboot and change it back to UEFI and turn back on Secure Boot, now all is well and good again.

Hope this helps someone in the future.

Yes, this was it for me exactly. Boot Sequence had lost the Windows Boot Manager path, but did still show the bare UEFI drive. I reset BIOS to defaults, added the entry

Boot option name: Windows Boot Manger

File name: \EFI\BOOT\BOOTX64.EFI

Rebooted and all good. Seems since then the BIOS has decided to re-recognise the SSD as OK to boot from and I now have two Windows Boot Manager entries, but as long as it's working I can leave it for now, but a bigger SSD, and rebuild.