Today I did install Ubuntu 14.04.3 LTS on a new PC (no dual boot!) After fine tuning the whole day, I did delete per accident the latest sub kernel of 3.19.0-30-gen. Now the pc do not start up at all, only the UBUNTU logo is visible. How can I repair this problem please, perhaps with the Live-CD or other programs or things? The Live CD is that the one I can dowload from the Ubuntu  site, so to try or install Ubuntu? Please help??!
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I was trying to delete old kernels, but I must have deleted all of the kernels on my Ubuntu 11.04 laptop. Is there any way to fix this via USB boot or mounting hard drive on another system?
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My machine was updated today to Ubuntu 16.04.2. However, the kernel is still "4.4.0-62-generic". What happened (it seemed that the principal advantage of the 16.04.2 version was the update of the kernel to 4.8) ? Do I have to make a fresh install ?
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I am a new user for Ubuntu. I downloaded 13.10 yesterday and made a bootable USB with universal USB installer on my Lenovo IdeaPad Z580 laptop which is now using UEFI; everything appeared OK.  When I booted from the LiveUSB I got the choices of trying or installing Ubuntu but both of them keep giving me these error:  [ 1.929082] kernel panic-not syncing vfs unable to mount root fs on unknown-block (0.0)   Please tell me what is going wrong?
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How do I access the recovery mode in Ubuntu 18.04? I don't see any form of grub bootloader when the system boots - it just goes straight into the OS.
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My question is, how can I find boot log from previous system boot attempt?  Today when first powering on my PC, boot process stopped on Ubuntu logo, when I pressed Esc I have seen several lines containing some kernel error and restart required at the bottom, so I pressed Ctrl+ALt+Del and next boot went OK without problems.  I have trouble finding messages from the screen I have seen during the first unsuccessful boot. Should I have taken picture to my phone?  /var/log/boot is there but empty, I searched  and  for strings I remembered with today's date like error but found nothing familiar to what I have seen on previous boot screen.  $ journalctl -b -1 gives me only kernel messages during boot, I can find that elsewhere too, and they are not what was appearing on screen during boot, journalctl is useless for me, I am looking for messages appearing on screen during boot time.  For now, only option is take a photo of write the message on paper.
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I know this may sound stupid, but I was having a problem with my ubuntu, it wasn't loading.   So I was googling solutions and one of them was purging something and installing something   so I did it. The proccess took a couple hours, and it didn't work. It turns out it was something to do with my graphics card (which I fixed), but when I loaded it up, I had lubuntu.   Is there any way of reverting back to ubuntu?   Or is lubuntu better to keep? I have no idea, please help.
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These two nice SE posts  comment on restarting one's ubuntu machine but they leave me with a few questions:   How do you actually do the restart (I'm a beginner and using 12.04.1 LTS)? Should I always restart the system when prompted to? Does restarting the system affect access to it via SSH or there any other caveats one needs to think about before doing this?
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I'm brand new to Linux. I just installed Ubuntu as a dual boot system on my HP Pavilion laptop.  Where should I start? I've tried to play around with Terminal over the last hour or so, but I'm probably not helping myself out. Any suggestions are welcome!
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After the most recent kernel upgrade, my system hangs during boot.  Since my machine seems especially persnickety about pulling up the grub menu*, what is the best way to set the previous kernel as the default until the next upgrade?  *I have to hit ESC at exactly the right moment, which usually means rebooting several times until I get it.
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I installed the latest updates from the software update center today (I update when ubuntu displays a notification), restarted the machine and now it's unable to boot properly. The best screen I can get is displayed below. If I resize the screen then it goes to black. If I restart the machine then it displays just purple.    Note that the screen is unresponsive, I can't click anything on it.  Other than SMBus Host Controller not enabled! I don't see any other warnings. Note that I don't know if this warning existed before the update.  I'm running ubuntu 18.04 in vwmare workstation 15 player (latest update). Any ideas on how to begin debugging this?    Update: Trying to boot Ubuntu, with Linux 4.15.0-50-generic instead of Ubuntu, with Linux 4.15.0-51-generic didn't help.  Update: Blacklisting i2c-piix4 according to  answer didn't remove the warning or fix the issue.  Update: Blacklisting i2c-piix4 according to  answer removed the warning but didn't fix the issue.  Update: The answer from Uzair helped me log into the account (run dpkg and update grub from recovery mode).  Answer:  answer helped me fully to resolve the issue. I don't understand the fix. If anyone does, put it as the answer and I'll mark it as such.  Regarding duplicity: The answer from another question did solve my issue but I don't think my question is a duplicate of that one. I began with a fresh install of 18.04 a few months ago, did several updates without an issue and only today experienced issues which are different than those described in the other question. I think we experienced different bugs with wayland and we both solved it by disabling it which is a destructive solution applicable to many questions.
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I have downloaded Ubuntu 10.10 and burned the ISO but it will not boot.   I discarded problems with the ISO, as I've downloaded from the official website with no errors, and burned it with no errors. I discarded problems with the burning, as looks like it was recorded with no errors here and later in another computer. I discarded problems with my DVD reader as other cds boots fine.   I'm currently using Ubuntu 9.10, I know I can upgrade via internet, but I have this same problem with my Windows XP cd, so I really would like to discover what's going on here.. My Ubuntu 9.10 cd boots just right, but the new one not.  What else can be? Or what more precise tests can I make to discover where's the problem?   --More info  What happens when I try to boot with the Ubuntu 10.10 cd is that it behaves like there's no bootable cd in the drive. It just don't find the boot on the cd, and start the HD system.  My notebook is an Amazon PC Intel Celeron 1.5 with 2Gb memory, a DVD-RW driver, HD samsung with 260GB.  --update  If you put the media agains the light and see the other side, does that means that it's a bad quality dvd media? (it's a Philips)
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This is NOT an installation problem question. I've had both op sys working fine side-by-side for a couple of weeks now. I'm using Ubunutu 12.04 64-bit.  This morning when I tried to switch from Win8 to Ubuntu, it just rebooted into Win8. No grub screen whatsoever. This is the 3rd machine I've had dual-booting &amp; have never seen this, but then Win8 is a 1st for me &amp; has thrown some pretty awesome blocks in the path to get to here. Atrocious op sys...  I'm assuming the ASUS updater did this yesterday. (ASUS R503U)  So, do I just put the Ubuntu disk in &amp; reinstall grub?
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I went ahead and installed windows 10 on my windows 8 and Ubuntu dual boot PC. All went smooth and Windows 10 works perfectly however the computer automatically boots to Windows and the grub launcher is missing. The partitions are still there I just need some help getting Ubuntu back. Thank you in advance!   Edit: I found a way around it. I don't know of this works for everyone but I went in to the control panel and went to update and recovery. Then I went to recovery and booted into uefi.  Then I selected boot from device and my Ubuntu partition was there and I could boot into it.  Feel free to post other solutions though!
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My ubuntu boot screen shows up in a strange low resolution, almost text mode, instead the usual and sleek white "ubuntu" over dark background. It's not a big issue because when GDM loads everything becomes ok, but If there's an easy way to fix it I would like to give it a try.
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So it's time to ask my first question, something I've been struggling with for a while now. I know there are some questions around the same topic, however, none of them (which I could find) have been of any help.  Before you ask, I want to do some explaining of the core problem.  Why have I not just installed it in UEFI mode?  I was unable to boot the install (or live mode for that matter) in uefi mode. After some time spent searching on google I noticed that several people have had this exact problem: after the menu appears (the uefi one), whatever I do simply results in a black screen.  After reading this article , I though I'd try installing ubuntu in legacy mode, and then use boot-repair to convert my install to uefi.   NOTE: I am dual booting ubutnu alongside Windows 10. Currently I have to enter the bios settings to enable uefi boot in order to enter windows and vice versa.   What I have tried  Boot-repair  I then tried, of course, boot-repair while in a legacy mode session only to get this error message:     The current session is in Legacy mode. Please reboot the computer, and use this software in an EFI session. This will enable this feature. For example, use a live-USB of Boot-Repair-Disk-64bit (www.sourceforge.net/p/boot-repair-cd), after making sure your BIOS is set up to boot USB in EFI mode.   Boot-repair live usb  I tried creating a live usb with boot-repair 64bit only to encounter the same problem as when booting the ubuntu install  Why do I need to boot with UEFI?  Well I don't REALLY need too boot using UEFI, however, my current windows install does, and it would be great to be able to choose whether to boot windows or ubuntu without having to switch between legacy and uefi.  Need any more information?  Is there a way to manually create the /boot partition and do the necessary changes for my system to boot efi?  Other suggestions?  Thanks  EDIT:  While I have tried both on and off, secured boot has been turned off for most of my attempts.  Edit #2: (In response to Rod Smith and comments regarding more info)   I have tried rEFInd boot manager, it encounters the very same problem I have tried rufus (Windows) and unetbootin (Ubuntu) for creating the usb media, both of which producing valid media (for other computers at least) I have a friend with (almost) the same computer with the same problem Very few distros work, Arch and Gentoo are among those who do work I have a GTX 1060 card on a Multicom laptop Windows does indeed use GPT and UEFI boot   Many of my assumptions have been made after reading this post right here:   Especially the text right after something describing my problem:     There is no solution for these errors and the workaround is to disable UEFI to enable the Ubuntu installer to run in legacy mode; after which boot-repair can be used to install grub-efi which then allows/needs UEFI switched back on before Ubuntu will boot using UEFI.   I actually assumed I couldn't reach the F6 menu at all, but now I haven't had time to recheck that.
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I installed or upgraded to Ubuntu 16.04, but I'm having some problems with my graphics card.   The display is blank The display flickers Items on the screen do not display correctly Certain programs complain of graphics issues The computer boots to low-graphics mode Your specific issue may not be here, but try the solutions described in the answers anyway.   This question is very broad, but each one of these issues likely has one solution.    If you are experiencing a login loop, check the last part of my answer.    If you experience one of the listed issues and have your own solution (mine didn't work, or there's a faster way), feel free to post another POLITE answer, describing your problem and how you fixed it.    Those attempting to install Ubuntu, please refer to the section titled: If you are unable to enter a TTY or are trying to install Ubuntu.
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I'm attempting to install Ubuntu 14.04.1 (the only version I have handy) onto my old Compaq Presario R3000 (this Ubuntu was recommended for this computer). The installation has stalled at about 60% and hasn't moved in an hour.  The message at the bottom says: Configuring bcmwl-kernal-source (i386).  I have no experience with Ubuntu (or with Linux, for that matter), coming from a strictly-Windows background). Can anyone offer some advice?