Using ISO image file to restore a laptop.?

firstly if it boots your os to the login, then there is no reason why it cant boot a usb stick. or the recovery media. if you tap f12 immediately after switching on, you can intercept the boot device menu list and choose the recovery DVD. in some BIOS's there may be a Enable/Disable boot from removable media too which must be ENABLE. in some cases you might also need to turn off uefi for USB boots as a USB device is treated as a legacy device, or there may be an Enable legacy device boot media option.. any way if you have a cd drive boot a hiren's to command prompt and create a new user and then start your pc normally and just login as the new user. from there you should be able to sort out the black screen issue. Hirens also has AV's you can run, or once booted Hiren's to MiniXP you can go online and use Trendmicro's Housecall to scan for latest threats. the black screen could just be a broken user account. with a new account you can usually just take ownership and move across all your other account files anyway from the command prompt of hiren's minixp.

We assume the ISO is a backup of your computer. The ISO image on the disk is simply a copy of a DVD image you need a DVD burning program to recreate the bootable and image files so you can restore the computer

It sounds like something else is going on with your laptop, are you able to access it's BIOS/UEFI pre-boot screen? Usually that involves pressing and holding down the DEL key before it boots up.

As for using the ISO on your external drive. You will need to attach that external drive to another computer, and have a DVD-burning software create a new boot DVD based on that ISO image. You can then insert the boot DVD to your laptop, and see if it will boot from it.

You have either Windows 8 or Windows 10 which is stuck in a warm boot environment now let me tell you how to overcome this problem one single time unplug your computer take the battery out pull the ram out put the ram back in then go ahead and put the battery in the power back in starting the computer and immediately hit the boot menu button that you have always use whether it be F12 Escape or F10 and it will boot to your thumb drive or your CD one single time before you have to repeat that process once you have removed Windows 8 or Windows 10 from the computer you won't have that problem anymore and I also suggest that before you go through all this that you make sure that secure boot is disabled and that Legacy support is enabled because if you had Windows 8 or 10 on there it may have secure boot enabled in which case you can't boot at all until you fix that problem