There is a problem with uefi support in ubuntu mate 15.10. I tried installing it on a external ssd, and I rebooted. it said “There is no bootable floppy. Press any key to reboot”. I had to manually install the grub-efi-amd64 package, and run the grub-install binary myself.
sorry for my poor grammar 
Hi,
did you switch UEFI off along with secure boot/quickboot, see the UEFI section here:
On my computer you can’t turn uefi off, and there is no secure boot implemented.
HI,
if you tell us the make and model of your PC; someone can help you further!.
Every PC that has UEFI on it has a switch(es) somewhere!. 
Here for example is a Lenovo PC:
http://www.daossoft.com/bios-tips/how-to-switch-from-uefi-to-legacy-on-lenovo.html
it is a Gateway ne56r10u
Hi,
try this:
Link taken from here:
Have you tried the F1 or F2 key when booting?.
I have went into the settings but no option for bios booting, and this originally had windows 7.
Hi,
download the manual from here:
http://us.gateway.com/gw/en/US/content/drivers-downloads
You should be able to access BIOS by pressing F2 when booting but if you have Windows 7, you most likely won’t have UEFI, so I don’t know why you need UEFI support for Ubuntu?. 
well I thought it had bios but i plugged in a arch linux live flash drive. The boot menu had a option for the flash drive, and a efi file on it.
Hi,
if your PC can boot to a USB without problems, then you don’t have a problem, you have actually created a problem by messing around with the UEFI file, it is not necessary on a Windows 7 PC!.
What exactly are you trying to do?, do you want to install Ubuntu Mate?, if so, follow this guide:
For partitioning:
what i was saying is that ubuntu mate didn’t detect that my laptop was uefi compliant and didnt install the uefi bootloader
Hi,
if you don’t have a UEFI based system (Windows 8 or 10) installed, there isn’t any real need for it as you are most likely already booting from “Legacy BIOS” and UEFI is indeed switched off!. So Ubuntu doesn’t really need to worry about whether or not the PC is UEFI compliant!.
Case when Ubuntu must be installed in UEFI mode
Having a PC with UEFI firmware does not mean that you need to install Ubuntu in UEFI mode. What is important is below:
if the other systems (Windows Vista/7/8, GNU/Linux…) of your computer are installed in UEFI mode, then you must install Ubuntu in UEFI mode too.
if the other systems (Windows, GNU/Linux…) of your computer are installed in Legacy (not-UEFI) mode, then you must install Ubuntu in Legacy mode too. Eg if your computer is old (<2010), is 32bits, or was sold with a pre-installed Windows XP.
if Ubuntu is the only operating system on your computer, then it does not matter whether you install Ubuntu in UEFI mode or not.
good well now i know