In this installation answer session for dual-booted desktop with two separate SSDs, the required procedure will be fully explained in detail.

The act of plugging and unplugging of SSDs from their sockets for dual-boot installation were discouraged and completely condemned because that act was going to harm your computer hardware.

This act of plugging and unplugging of SSDs have been practiced by a few just to avoid "an extraneous GRUB entry is being installed on the EFI Boot Partition of the Windows 10 SSD". It is wiser to attempt to remove such an extraneous GRUB entry instead of practicing this 'harmful' method of dual-boot installation. The removal of this extraneous entry is the role of Part-IV of this answer-session.

You should never unplug anything and never mess around your computer Hardware.

• Plugging & unplugging SSDs may cause neighboring components connection issues and your computer may not start or malfunction and is difficult to diagnosis.
• While unplugging SSD with tight socket fittings, you may apply force which may disturb the other parts of Motherboard and there will be always the possibilties of creating loose connection. i.e. if you work on one component and if you are little careless, you may disturb others. I did once a blunder and my front-panel audio and USB ports were stopped working. It tooks me days to identify the problem and resolve it. It was simply a loose connection!
• If you have not properly plugged SSD back into socket tightly, this will create a situation which is hard to diagnosis because computer will work sometimes and suddenly there will be malfunction. May be read/write errors and so on.

---

Part-I: Install Windows 10 on first SSD (/dev/sda)

The first mistake was to purchase identical 250 GB SSD of same make. If I were you, I would go for a Kingston 250 GB SSD and a Samsung 250 GB SSD. When you open up BIOS setup screen you can immediately observe the bootloaders bearing the SSD brand. This will be helpful to find out what is where. Whenever your PC is opened up later for any reasons, from the color of SSDs itself, you can tell that, for example, Windows-10 was installed in 250 SSD Kingston (red in color) and Ubuntu was installed on Samsung 250 SSD (some other color) respectively.

While installing windows-10, you will see two devices appear in front of you and you will be asked to select any one to continue with installation. Select /dev/sda for windows-10 installation. This way you will always remember that sda is meant for windows-10 and you will always remember it.

You should never partition SSD! Allocate entire 250 GB to 'C' drive and have all the windows related systems and other programs in 'C' drive. Never keep any data in SSD.

Suppose you wanted to install complete Visual Studio Community 2017 RC (a free, fully featured version), then it is going to take around 80 to 90 GB of 'C' drive.

Other point of suggestion, is go for a hard disk at least 1 TB size. You need a place to keep your data, downloads and other stuff without disturbing your SSDs.

The following link gives you step-by-step installation of windows-10. Just follow the link and you must get Windows-10 installed.

Windows 10 Installation step-by-step

After Windows-10 installation, you complete the formalities such as installing cumulative/security updates for your build version and so on. After finishing them along with other essential tasks, then you may resume back your journey towards installing Ubuntu 18.04.

---

Part-II: Install Ubuntu 18.04 on second SSD (/dev/sdb)

As you have already admitted in your question is that your new to Ubuntu.

I welcome you to the fascinating world of Ubuntu whole heartedly.

I also made my Ubuntu entry recently, like you, just 7 months ago!

The first complexity begins during the installation is to partition your 250 GB SSD. There are varied theories exists and no second person agree with your partition! There is always a debate because every body is right!

I have a 120 GB SSD where Ubuntu was installed. Here is my partition details:

Sl.No:  Partition  File System           Device         Allocated Size   Partition Type
1       efi        FAT32                /dev/sda1       0.5 GB           Primary
2       swap       Swap area            /dev/sda2       16 GB            Primary
3       /          ext4 with journaling /dev/sda3       6 GB             Primary
4       /usr       ext4 with journaling /dev/sda4       16 GB            Primary
5       /opt       ext4 with journaling /dev/sda5       44 GB            Primary
6       /tmp       ext2                 /dev/sda6       16 GB            Primary
7       /var       ext4 with journaling /dev/sda7       8 GB             Primary
8       /home      ext4 with journaling /dev/sda8       13.5 GB          Primary

I arranged this partition setup particularly with Oracle 18c (Enterprise Edition) in mind. I would never ask you to follow my foot steps. Please never do that! You may have 2 partition or 3 or sometimes no partition, it is up you. This is the toughest part for a new entrant like you to negotiate with.

So, please do a thorough planning before you begin installation.

My partition table serves you as an example for an understanding of what partitions are. You may begin installation once your partition plan is frozen.

Next, during installation, at the time of dividing your SSD into partitions, be careful enough to select /dev/sdb. Because device /dev/sda has Windows-10 already installed. Once you cross this hurdle, the remaining part of installation is a cakewalk.

Now follow this link and you can easily install Ubuntu 18.04. This step-by-step procedure covers extensively regarding partitioning and teaches you how to do that.

Ubuntu 18.04 Installation step-by-step

---

Part-III: Post Installation of Ubuntu 18.04

1. Setup WiFi: Configure WiFi connectivity if you have one.

2. Setup Password for Firefox Browser: Configure Firefox Browser with email-ID

3. Set the Root password.

Set a password for root user in a single go:

$ sudo passwd root

Test it your root password by typing the following command:
$ su -

4. Disable lock screen.

To disable lock screen just follow this:

Settings -> Privacy -> Screen Lock -> change 'Automatic Screen Lock' to 'Off' 

To disable lock screen through command line permanently, issue the following command:

$ gsettings get org.gnome.desktop.lockdown disable-lock-screen 'true'

If you are unhappy with the new setting you can reverse it using:

$ gsettings set org.gnome.desktop.lockdown disable-lock-screen 'false'

Figure-1: Disable Screen Lock

5. Adjust the Dock-styled Launcher

Ubuntu includes a dock-styled launcher (also known as "dock") on the left of your screen. If you don't like its position and the size of the icons on the launcher, you can adjust it easily through the settings.

1. Click the Applications button and select "Settings".
2. Select "Dock" on the left column.
3. On the right column, drag the slider of "Icon Size" to the left for a smaller size, or right for a bigger size; and change the dock position to the bottom or right of the screen.

Similarly, you can also auto hide the dock.

6. Install Updates:

$ sudo apt-get update           # Fetches the list of available updates
$ sudo apt-get upgrade          # Strictly ugrades the current packages
$ sudo apt-get dist-upgrade     # Installs updates (new one)

If you have successfully upgraded, then you move on to step-7.

If there are any issues due to "metered" internet and upgrade command interrupted, then upgrade can be resumed through following command:

$ sudo apt-get install --fix-missing

And then issue:

$ sudo apt-get update
$ sudo apt-get upgrade

7. Install aptitude

$ sudo apt-get update
$ sudo apt-get install aptitude
$ sudo apt-get dist-upgrade

8. Install Grub Customizer:

Grub Customizer is a graphical interface to configure the grub2. The application allows the user to add, remove, freeze, rename and reorder boot menu items.

Open up terminal by hitting Ctrl+Alt+T and run following commands one by one:

$ sudo add-apt-repository ppa:danielrichter2007/grub-customizer
$ sudo apt-get update
$ sudo apt-get install grub-customizer

How to use?

• Once installed, hit Gnome dash and search for "G" and double-click Grub-customizer icon to open up. Figure-2: Type 'G' in search box in order to cause 'Grub customizer' to appear
• Grub Customizer will always request you for authentication. Type your sudo password. Figure-3: Type sudo password authentication
• Now using this graphical tool you change the boot order of GRUB by bringing up Windows bootloader to the top of the chain. This can be done by moving the desired loader up until it reaches the top. Figure-4: Place the cursor on 'Windows bootloader', then right click for drop down menu to appear and use 'move up' menu item to lift 'Windows bootloader' up in the ladder until you park it on the top.
• Once Windows bootloader parked at the top of the ladder, the first thing you should do is save the settings. There is a save menu item at the top-left and click that to save your GRUB configuration. You should never ignore this step!
• So by default windows-10 which you have set will be booted after 10 seconds. Just click General settings marked by a red arrow to get the following figure-5, where you can alter this 10 secconds delay interval. Figure-5: GRUB interval 10 seconds may be altered here
• You can always explore this tool without any fear because you can always quit from the tool without saving!
• This is how you configure Grub using Grub Customizer tool. Very reliable!

9. Now Reboot your system

Check the GRUB menu which should contain Windows bootloader at the top of the chain.

10. Now Log into Windows System

We have the following important task to complete before bringing this procedure to conclusion.

---

Part-IV: How to delete "extraneous" GRUB files from a Boot EFI partition in Windows 10?

What is this extraneous GRUB files?

This entry is done by GRUB (refer figure-8) after Ubuntu has been installed.

Whenever you do a dual-boot installation, this is an unwanted gift you will be presented with. This is reflected in BIOS setup screen as boot option #3 (refer figure-9).

Nevertheless, we will remove this extraneous gift subsequently. After this removal, BIOS setup screen will contain only two entries (refer figure-13).

Before proceeding further, I must introduce you my desktop configuration, otherwise it is difficult to follow the screenshots which you are going to face subsequently.

My system is a dual-booted desktop with a 250 GB SSD (Windows-10 installation), another 120 GB SSD (Ubuntu 18.04 installation) and 1 TB hard disk with three NTFS partitions which are mounted on Ubuntu as CodeWrite (read-only), ShareMe (read-only) and Warehouse (read-write) respectively. So, this 1 TB hard disk is sharable between Windows-10 and Ubuntu 18.04. All the copies of installable downloads not only for Windows-10 but also for Ubuntu 18.04 are kept under ShareMe. This arrangement helps to preserve storage space on both SSDs!

Note-1: When I assembled my desktop, I went for two 120 GB SSDs. I planned my desktop very carefully right from the beginning, made sure that my motherboard should have in-built Wi-Fi as well as Bluetooth and so on. The only blunder I committed was that I never anticipated that Visual Studio Community 2017 will take up my entire 'C' drive! This fellow has simply eaten away around 78 GB disk space on my 'C' drive. Thus, this oversight has costed me double the money, i.e I had to re-invest again on SSD by replacing the 120 GB SSD with a brand new 250 GB SSD. How much ever careful are you, sometimes you slip! So this was my story.

Note-2: The screenshots were all taken when I had two 120 GB SSDs of identical size. Please bear this in mind.

Press + X and select Command Prompt (Admin) and run diskpart command.

Figure-6: Using 'diskpart' to list hard drives detected on Windows 10

After the target disk has been selected, its partitions are listed, so that the partition (volume) that corresponds to the Boot EFI folder can be identified.

In figure-7 below, that partition is Volume 3. It’s usually the only volume with FAT32 in the FS (file system) column, and System in the Info column. After it has been identified and selected, you assign it an unused drive letter to make it easier to work with. In this example, I assigned it a drive letter G.

DISKPART> sel vol 3

Figure-7: Select volume number corresponding to the EFI partition and assign a drive letter

The final task involves changing into the Boot EFI folder, listing its contents to identify what subfolder the GRUB files would be. It will be in the EFI folder. The GRUB files for the distribution that was installed will be under a folder of the same name as the distribution.

For example, if Ubuntu was installed, as in this example, the name of the folder will be ubuntu. Delete the folder using the rmdir /s command. That’s the Windows 10 equivalent of the Ubuntu Linux rm -r command.

Figure-8: Removal of extraneous 'ubuntu' boot entry from windows-10 EFI

To make sure that ubuntu has been removed, issue dir command again:

DISKPART>dir /B

The output will show only two entries.

Exit from diskpart command.

Figure-9: GRUB has created an extraneous boot entry in SSD (Kingston) drive where in windows-10 installation exits.

Now Look at the three boot entries in BIOS as shown below:

The Boot option#3 is the culprit which should be removed not only from SSD (Kingston) but also from GRUB boot loader:

We have already followed the steps in the beginning of Part-IV (How to delete "extraneous" GRUB files from a Boot EFI partition in Windows 10?) until now and removed the extraneous ubuntu directory from windows-10 EFI successfully.

Now restart computer and login into Ubuntu system.

Open up terminal by hitting Ctrl+Alt+T and run following command:

$ sudo efibootmgr               # issue this command to show boot entries

Figure-10: Output for command: 'sudo efibootmgr' showing 3 entries

Boot entry 2 should be removed. How to confirm this?

$ sudo efibootmgr -v                    # issue this verbose command

Boot entry 2 has the same UID for SSD disk as boot entry 0 which is windows loader.

$ sudo efibootmgr -b 2 -B               # where 2 is the boot entry Boot0002.

Now the entry has been removed.

Figure-11: The process of removal of the extraneous boot entry created by GRUB

To confirm the removal, just issue the following command:

$ sudo efibootmgr                   # issue this command to display boot entries

Figure-12: Confirmation of removal of extraneous boot entry created by GRUB

From the figure-12, it is clear that only two entries are present rather than three. Just see the entries marked with *.

Let is finally see BIOS setup screen below figure-13, to make sure that only two boot loaders are present.

Figure-13: The extraneous 'Boot Option #3' has been totally removed from BIOS (compare with Figure-9).

Part-V: Conclusion

In this installation answer session for dual-booted desktop with two separate SSDs were fully covered.

The act of plugging and unplugging of SSDs from their sockets for dual-boot installation were discouraged and completely condemned because that act was going to harm your computer hardware.

This act of plugging and unplugging of SSDs have been practiced by a few just to avoid "an extraneous GRUB entry is being installed on the EFI Boot Partition of the Windows 10 SSD". It is wiser to attempt to remove such an extraneous GRUB entry instead of practicing this harmful method of dual-boot installation. The removal of this extraneous entry is the role of Part-IV of this answer-session.

The Part-IV covers in detail the extraneous entry introduced by GRUB in windows 10 efi partition which was also reflecting on BIOS setup screen. This part provides detailed instructions to remove the extraneous entry not only from Windows 10 efi partition but also from BIOS setup screen one after another.