Original Question
=================

I'm trying to install Xubuntu on a 2015 Dell XPS 13 laptop, but I've been running into all sorts of bootloader-related problems. To make a long story short, I've installed several different distros on this machine over the past few weeks, but the trouble didn't begin until after I installed Fedora 21. Here's a quick summary of events:

* I originally installed Xubuntu 14.10 and 15.04 Beta 1 alongside Windows 8 without any problems.
* I erased the entire disk and installed Fedora 21 using LVM with encryption and the default partitioning scheme.
* I've attempted numerous times to erase the entire disk and install Xubuntu 14.10 and Xubuntu 15.04 Beta 1 using various partitioning schemes. Sometimes I get an error message stating that GRUB installation failed. At other times, the installation completes without error, but when I reboot my machine, Ubuntu is not detected as a boot option. Unfortunately I don't have any error logs available from the times when the GRUB installation failed, and I haven't been able to reproduce that specific problem recently.
* I tried erasing the disk and installing Fedora 21 again, and the installation completed successfully. I could boot into Fedora without error.
* I again attempted to erase the disk and install Xubuntu and Ubuntu 14.10, but I encountered the same problems as before: the installation completes successfully, but there are no entries in the Dell boot menu.

I'm using UEFI with Secure Boot disabled for all of this. All I want to do is to erase the disk and perform a standard installation of Ubuntu or Xubuntu with no other operatinng systems installed. 

Currently I have Xubuntu 14.10 (and no other OS) installed, but it's not showing up in the boot options when I turn on my machine. I've tried running boot-repair, and it's giving me this message:

> 
> GPT detected. Please create a BIOS-Boot partition (>1MB, unformatted filesystem, bios\_grub flag). This can be performed via tools such as Gparted. Then try again.
> 
> 
> 

I'm confused by this, because I'm booted using UEFI. (`/sys/firmware/efi` is present.)

I realize that this is not a lot of information to go on, but I'd be extremely grateful if anyone could point me in the right direction or suggest what might be causing this problem.

Background
==========

In case it's relevant, I'm running the Dell A03 BIOS on this machine. I replaced the stock Broadcom wireless card with an Intel 7260NGW while Fedora was installed in order to get better out-of-the-box networking support without messing with proprietary drivers. That hasn't caused any obvious problems.

Everything described here was done in UEFI mode with Secure Boot disabled using 64-bit ISOs.

I've tried creating installation media using both Startup Disk Creator and `dd` and encountered problems in both cases.

I've been jumping between distros in an effort to find something with a relatively recent kernel that plays nicely with this machine. I've been trying to install Xubuntu 15.04 Beta 1 rather than Beta 2 in order to avoid [this bug](https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1436715).

Summary, Speculation, and Questions
===================================

I've tentatively ruled out the following possible explanations (but feel free to correct me if I'm mistaken here):

* Bad USB drive
* Improperly created installation medium
* Booted in wrong mode

It seems like something changed after I installed Fedora, though I suppose that could just be a coincidence. But here's what's puzzling me:

* Why would installs conducted after formatting the partitions repeatedly fail to properly install a bootloader? Shouldn't a fresh, standard installation of Ubuntu work 99% of the time?
* Why has the installer displayed "failed to install bootloader" errors on some occasions but completed without error on other occasions?
* Why am I getting errors about BIOS compatibilty mode when I've been using UEFI and GPT all along?

Terrifying possibilities that I've considered but don't know how to diagnose:

* There's something wrong with my laptop's hardware.
* There's something wrong with the Dell BIOS.
* Fedora made some sort of change to the disk that's persisted despite my repeated attempts to format it and install Ubuntu.