I installed XUbuntu on a fast usb key on a new computer using UEFI mode. When I try to boot on this usb key with a old computer, it doesn't work.
After F12 and selected USB, the screen is black with an horizontal cursor is blinking. Obviously, the MBR is not set up or my bios doesn't support GPT tables. (laptop from 5years ago)
Where and how to check if my usb key is able to being booted on both ways ? In the case the MBR boot is unable, how to create it beside the UEFI mode ?
The CPU is an Intel Core2Duo T9900. The USB stick is a Sandisk Extreme 64GB. It's pretty weird because my windows 7 is a 64bits version and of course XUbuntu installed is the 64bits version.