Make sure that you set your USB device as the first boot device in BIOS so you could access the USB. Also most of the time laptops has a built in Recovery partition where you could reformat your PC without any use of a USB or a created USB boot drive. Do check your laptops user manual on how you can run a Factory Reset.
1:Restart your computer and wait for that first screen to pop up. Often, it'll say something like "Press F12 or Delete key or F2 key(mostly in asus laptop its delete key) After Pressing the key ,Boot Menu will come up.
2: Go to boot options by navigating your arrow keys on your keyboard
3: Select Boot priority by hitting enter key and select the first boot priority to Usb device and second priority to Hard disk.
4: save using F10 button and system will restart automatically and it will ask press any key to boot from usb .Just press any key to boot. Thats it.. Done.
recently i just purchased a new laptop and I am having issues when booting it, I already loaded an .ISO file to my pendrive and when I start the pc it doesn't read thep endrive.
If you just got a new laptop, why are you trying to boot off a USB stick? If you are trying to replace the operating system for some reason, did you just copy the ISO file to the USB stick or did you actually create a bootable stick using the ISO file? What ISO file and where did you get it? Are you able to select the USB stick as a boot device but it does not find a boot drive there?