So, on my HP650 i have internal HDD on which i have windows 10. I installed Ubuntu 18.04. on external HDD which is connected via USB.  The problem is that GRUB menu doesn't show up at start, so I can't choose which OS to run, it goes to windows. Only way i can boot Ubuntu is manually, by pressing esc during startup, entering boot device options, and selecting Ubuntu.    These are boot options and boot order in bios   I also tried changing boot order in Ubuntu terminal with no luck.  I disabled fast startup in windows.   Any ideas?
I have installed Ubuntu 15.10 alongside Windows 10 with UEFI. To install Ubuntu, I chose the option install alongside Windows 10 or something similar to this. Then I created a new partition for Ubuntu and installed it. After installation, the boot menu did not show up. Initially I thought Ubuntu has not been installed, but when I plugged in the USB drive and wanted to install Ubuntu I saw an option of reinstalling Ubuntu on my machine. So, I found out that Ubuntu is installed. Pressing F8 and F12 also does not help. Can anyone help me bring up the GRUB boot menu? In Windows, I also entered the command bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi in cmd, but still the boot menu does not show up.  Reply (Himanshu) : Just boot in bios and, if you can, add boot option with name say ubuntu and path EFI/ubuntu/shimx64.efi. No need for live PCB or anything. Move the boot option to top. This is for dell GUI bios but I assume it works for all. Or you may want to see  or , where you can enable Windows Boot Loader for one boot or forever as you wish, and boot Ubuntu from it. If you want now, you can use the installed Ubuntu terminal to use the commands update-grub to use GRUB instead. (Not enough reputation to answer properly btw.)
32-bit vs. 64-bit systems What are the differences between 32-bit and 64-bit systems?  If you have used both of them, what kind of sharp differences have you experienced?   Would it be a problem to use 32-bit programs on 64-bit systems in some cases? I saw the sentence like     Donald Trump to run for president next month.   in the newspaper on the internet.  But I don't know why we have to use to instead of will.  Is there any rule I don't know?  Can anyone tell me the reason why we should use to in the news? how to create a histogram in java I'd like to know how many downloads of a given package in a PPA there have been since it was first published.  I remember there was  about it about getting these metrics on the web UI, but as far as I know, it never got implemented.  But I think the number of downloads can nevertheless be obtained via the  if I'm the owner of that PPA. Any pointers? Rotation of rigid body with two different angular velocities Consider a cylinder that rotates about a vertical fixed axis with angular velocity $\vec{\Omega}$ while rotating about  a vertical axis passing through its center of mass with angular velocity $\vec{\omega}$.    Now the two angular velocities of rotation $\omega$ and $\Omega$ are not the same I suppose and there is no link between the two angular velocities, is that right?  Firstly what is the angular velocity of the rigid body? I suppose that it is  $$\vec{\omega^{*}}=\vec{\omega}+\vec{\Omega}$$  But why?  And then what is the moment of inertia with respect to the axis $z$ of the rigid body? If I use parallel axis theorem I get  $$I_{z}=I_{cm}+mR^2$$  Where $R$ is the distance from $z$. But that doesn't seem right. The cylinder is not rotating about its center of mass at the same angular velocity of rotation about $z$. So using $(1)$ give some incorrect results. For istance kinetic energy  $$K=\frac{1}{2} I_{z} \vec{\Omega}^2= \frac{1}{2}(I_{cm}+mR^2)\vec{\Omega}^2$$  But that's the kinetic energy of a body rotating about $z$ and center of mass with the same angular velocity $\vec{\Omega}$, and this is not the case.  I'm confused, can anyone help me with give suggestion about angular velocity and moment of inertia in problems where the rigid body is rotating at the same time about two different axes? Where can I find a list of all the Stack Exchange sites?  I need to ask a question about cars (where my total knowledge is about zero) but I can't find a cars Stack Exchange site - tried guessing all the obvious (and pun based) names.  I assume the list of a dozen or so at the bottom of this page is only a subset? There must be a site on a topic as geeky as cars!  A list of future/beta sites would also be useful - I found a few on topics I'm interested in only after they had been up for a while. Can a 3rd party charger damage my macbook pro? I am thinking of buying a digital SLR camera. What things should I be looking for? Downloading all photos from iCloud Photo Library without Photos app If I solve someones problem instead of answering their question, should I post a comment instead? When an air-filled balloon is released without its opening tied up, it moves in a circular path rather than a straight line. Why is that? I added a user to a group, but group permissions on files still have no effect I changed permissions of a file (chmod g+w testfile) and running ls -l testfile gives:  -rwxrwxr-x 1 user1 user1 0 2011-01-24 20:36 testfile   I then added a user to that group ("/etc/group" has user1:x:1000:user2 line), but am failing to edit that file as user2. Why is this so? Conventional parenting wisdom tells us to drive the fear of talking to strangers into our kids. Is this at all harmful though? Is there any adverse impact to a child's social development by doing this? How can you balance safety against fear? Tracking disk I/O by application in Windows? Connected graph with colored edges We have connected undirected graph with colored edges in two way (green or blue). And also each vertex have the same number of green and blue edges. How to prove that there are alternate colored (green-blue) path between any two nodes? I can't get into my field research prize Show that the determinant of $A$ is equal to the product of its eigenvalues Show that the determinant of a matrix $A$ is equal to the product of its eigenvalues $\lambda_i$.   So I'm having a tough time figuring this one out. I know that I have to work with the characteristic polynomial of the matrix $\det(A-\lambda I)$. But, when considering an $n \times n$ matrix, I do not know how to work out the proof. Should I just use the determinant formula for any $n \times n$ matrix? I'm guessing not, because that is quite complicated. Any insights would be great. I know that hardly any information is passed to the PDF when a .tex file is compiled.  But is there a tool that can convert a PDF document back to (La)TeX? Let $\alpha,\beta,\gamma$ be the roots of $x^3-3x^2+1 = 0$. Prove that $$\alpha^n+\beta^n+\gamma^n \equiv 4^n+5^n+(-6)^n \pmod{17}$$ where $n$ is an integer.   It sort of makes sense why they are congruent since we can say $x^3-3x^2+1 \equiv (x-4)(x-5)(x+6) \pmod{17}$, but since $\alpha,\beta,\gamma$ aren't integers, how do we prove this? TestMethod do not support Web service callouts, test skipped