Solution to starting Windows with external hard drive connected

I had a problem starting Windows after adding a new external backup hard drive - the computer froze at boot. I could boot into Windows with external hard drive disconnected. After getting into Windows, I could add the external hard drive which would show up in My computer and I could access it But this was not accceptable to me. I finally called Dell Support. She then guided me to the download section for my computer and selected the BIOS file and I made sure the external hard drive was connected,. We download the file, and flashed the BIOS in my computer. After rebooting, I could then boot into Windows with the external hard drive connected. The BIOS was now recognizing the external hard dive before the starting windows.

This can happen with any USB drive that has also been formatted to be bootable, by boot code remaining even after the installation files are removed.

If you have a USB flash or external drive that blocks the OS from booting, move the data off to wipe the drive with Diskpart Clean Command which clears the boot sector and partition table of all code, then repartition as a data drive in Disk Mgmt.