Need Help Installing Windows 7 via USB

I have formatted and copied windows 7 to my 4GB USB key and I have installed a new HDD into my Dell Optiplex 745. When I boot up the computer I am notified with:

PXE-E61: Media test failure, check cable
PXE-M0F: Existing Broadcom PXE ROM

I have searched and found out that this can be caused by a bad hdd but this can't be the case seeing that I literally opened it new from it's packaging and instantly installed it. Also I heard that in order to install via USB you need to place USB to #1 in boot sequence. I have tried this but when I do this all I get is a screen with a flashing underscore at the top of the screen and I can't do anything. So I changed my boot sequence back to the way it was:

1. Onboard or USB Floppy Drive (not present)
2. Onboard or USB CD-ROM Drive
3. Onboard SATA Hard Drive
4. Onboard Network Controller
5. USB Device

I have no backup disk and I have no access to a Windows 7 DVD, all I have is it on USB.

Any help would be greatly appreciated.


Excellent Member
Microsoft Community Contributor
Did you make the flash drive bootable? There are many tutorials on how to set that up if you have not already looked at those.

Some Dells use an F12 key during boot to select a boot device. Are you getting a message like that?

When you tried the boot sequence you had the USB device listed first? There may also be an entry to allowing to a USB device in another part of the bios setup.

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