Can't boot OS from USB drive, showing black screen with blinking cursor

Solution 1:

Just to make sure I'm getting the right question:

• Your computer is an Acer TimelineX 3820TG, which as a mobility unit has no optical drive
• The computer shipped with Windows 7 Home Premium
• You wiped it with Mandriva which you installed sucessfully via USB
• You decided you didn't like Mandriva and reformatted the computer with Windows 7 Professional, also from a USB Key
• You decided that you'd like to dual boot with Ubuntu/
• However after multiple attempts to create a USB Install disk, including using the Universal USB Installer, you can't get the machine to go past the blinking cursor

It sounds like your flash drive may be the issue here and it may need to be re-paritioned.

Did you try checking the Erase flash drive box in the U-USB Installer?