![Why the screen below appear when I boot my dell Inspiron 7559? And dell logo doesn't appear? Therefore I can't access BIOS utility to boot the laptop from a USB flash drive. : Why the screen below appear when I boot my dell Inspiron 7559? And dell logo doesn't appear? Therefore I can't access BIOS utility to boot the laptop from a USB flash drive. :](https://i.redd.it/rans60nch4441.jpg)
Why the screen below appear when I boot my dell Inspiron 7559? And dell logo doesn't appear? Therefore I can't access BIOS utility to boot the laptop from a USB flash drive. :
![Whenever I load up my Dell Vostro this screen appears... I've tried getting into BIOS setup using F2 and F12 keys and repeatedly hitting those on startup but to no avail. I've Whenever I load up my Dell Vostro this screen appears... I've tried getting into BIOS setup using F2 and F12 keys and repeatedly hitting those on startup but to no avail. I've](https://i.redd.it/yyqj7r2q30941.jpg)
Whenever I load up my Dell Vostro this screen appears... I've tried getting into BIOS setup using F2 and F12 keys and repeatedly hitting those on startup but to no avail. I've
![FIX: Dell Laptop - Operating System Loader signature not found/invalid. (Solved) - wintips.org - Windows Tips & How-tos FIX: Dell Laptop - Operating System Loader signature not found/invalid. (Solved) - wintips.org - Windows Tips & How-tos](https://www.wintips.org/wp-content/uploads/2018/01/image-43.png)