Dec 15, 2014

Why won’t my PC boot with flash drive plugged in?

This is not exactly a big problem, since I can easily resolve it by removing the flash drive, but I’m curious why this is happening. I’ve used other computers that had no issue booting with a flash drive left connection, but on my Lenovo I get an error: “no bootable partition found in table.” Why is this causing my Windows 7 PC to not boot?
Why won't my PC boot up with a USB device plugged in?

"This is a basic safety feature on laptops and PCs. The idea is if Windows is corrupted or the hard drive fails the computer can still be booted from a recovery CD/DVD or USB drive. At switch on PCs run through a short self-diagnostic program called the BIOS (Basic Input Output System). One of its functions is to tell the computer where to look for boot files. Usually the CD/DVD or USB drive is first, and if no files are found it boots normally from the hard drive and loads Windows. The solution is to change the Boot Order so the hard drive is the first boot device. "
BIOS will sometimes be configured to try to boot off USB before any other drive, and that is probably the case here. The result is that when that flash drive is plugged in, the PC looks there and doesn’t find a bootable partition. You can either go in and configure BIOS to change the boot sequence so it will boot off the HDD or, as you rightly noted, unplug the flash drive.
Answer this