Where did I install Ubuntu?

Question

Screenshots of my drives as they stand:

I completely lost what I was doing when I installed Ubuntu, intending to dual-boot it with Windows 10. First, while in Windows, I partitioned off 25GB of my 1TB hard drive and named it Linux_OS (L:). I went to install Ubuntu from a USB, and when it got to the screen where it was supposed to ask me to install alongside Windows, it told me it didn't recognize an existing operating system. I hit "Something else" to manually install it to the Linux partition I had created. The screen confused me but I thought I had it figured out: all of my partitions were there, but they were listed as some ridiculous name. At the end of each one was "p1", "p2", "p3", up until "p6". p6 had 17GB free on it so I assumed it was the lastest partition I had created: Linux_OS. I selected it, put "Ext3" for filesystem and hit "/" as the mount (honestly still don't know what that meant). I put the same drive as the bootloader (this also confused me) and installed Ubuntu. Now I have Ubuntu installed, but I checked the Linux_OS drive and it's completely empty, marked as NTFS; Ubuntu was installed somewhere else. I have no idea where though - I think I may have overwritten some part of my Windows drive.

On startup, Windows still boots up as default. I figured out I can get to Ubuntu by searching "BIOS" and hitting the button that boots the computer from another source.

If anyone can explain what exactly I did to my computer, I would greatly appreciate it. In addition:

1. What exactly is a mount point?

2. What is a bootloader?

3. How can I get the computer to ask me which system I want on startup?

4. What is this GRUB thing I keep hearing about?

Sorry if these questions may sound simple, but I'm pretty lost. Thanks.

Answer 1

Your last 3 question are all related. GRUB ≈GRand Unified Bootloader, which is the Linux way of loading operating systems on boot. GRUB can be configured to load Windows in a dual boot configuration. When GRUB is set up correctly, you'll get the famously ugly GRUB menu at startup, which gives you a choice of OS's to boot into. If you don't see a GRUB menu, something's wrong. I would suggest using your Ubuntu CD to do a GRUB repair. How to do this exactly depends on if your computer is set up with legacy BIOS or UEFI. I'll give you some links later. A mount point is where you, or programs, looks for a file system, which could be a folder, or an entire hard disk. For example, Linux could be installed on hard drive partition sda2, but for it to be used, it must be mounted to "/". You look for things in "/", not sda2. It something like "c:\" in Windows. First of all, let's try to find that lost Ubuntu installation. Boot into your Ubuntu live CD (Try Ubuntu without installing) When you get to the desktop, open a terminal( Ubuntu menu/type "terminal", click on the icon that looks like a black computer monitor). In the terminal, type : sudo fdisk -l (last character is "l" as in "lemon") And hit enter. You'll get some information about which hard drive partitions you have( /dev/sda1 etc.) ,size of each, and partition type: ntfs, ext, whatever. Make note of this information. Open the Nautilus file manager program. Look on the left side of the window for anything that looks like a hard disk, and click on them to mount them. Now go back into the terminal window and type: df -h And hit enter. This will display information about active mounts, where they're mounted, and how much space is used and free on each. With this information, provided that Liniux really is installed on on of those partitions, you can do a GRUB repair. Here are some links on how do do that:

http://howtoubuntu.org/how-to-repair-restore-reinstall-grub-2-with-a-ubuntu-live-cd

For UEFI, you'll need to add a couple more steps:

Can I install in UEFI mode with the alternate installer?

Hope these links help.