This question may seem repeated but I have other more issues. I installed 8.1 in my dell 5537 and dual booted it with ubuntu 14.04..I worked well..I installed with alongside windows option..It took 30gb(as I selected the space) space from my logical drive which was last drive...I have four partitions c:,D:,E:,F:(or local drives). Now I deleted the ubuntu from disk management(as there was some problem in ubuntu and i could not fix it).I fixed the windows MBR with live CD. I now want to dual boot ubuntu 15.04 again..I have changed boot mode to UEFI(with secure mode disabled) I get grub to install ubuntu. I clicked install ubuntu. Now i get the Message of

"force UEFI installation?...this machine's firm ware has started the installer in UEFI modebut it looks like there may exist operating systems already installed using "BIOS compatibility mode"...If you wish to install in UEFI mode and dont care about keeping the ability to boot one of the existing system,you have the option to force that here......".

Now if i force UEFI i cannot see any of my partitions of windows and see my whole disk as 500gb disk(as /dev/sda ntfs) and no option of new partition table or other disk...It will erase my whole disk.....I have already shrinked volume from C: and divided that space into 3 part (one primary and active ,two logical).

I use mostly windows and don't want to lose any data from any disk and volumes.. I am not familiar with linux much...So please help with detailed steps...


First, you need to be aware that there are two methods of booting most modern computers:

  • BIOS/CSM/legacy mode -- This mode is what was used on most computers prior to about 2011. It uses either an old-style BIOS firmware or BIOS emulation ("CSM" or "legacy") on a more modern firmware. It's usually paired with an MBR partition table. Note that on a modern computer, BIOS/CSM/legacy mode is the non-native boot mode; using it is like using WINE to run Windows programs in Linux.
  • EFI/UEFI mode -- Modern firmware uses the Extensible Firmware Interface (EFI) or its 2.x variant, UEFI. UEFI-mode booting is completely different from BIOS-mode booting and almost always uses a GUID Partition Table (GPT). Unfortunately, there's a lot of misinformation and bad advice about EFI-mode booting, which is making the transition from BIOS to EFI harder than it should be.

I strongly recommend you read up on these subjects. The Wikipedia articles referenced above are a start, although they're a bit dry and divorced from practical concerns. Three others you might read are:

It sounds like you've converted from an EFI/GPT setup to a BIOS/MBR setup, but you did so with a tool that does an incomplete GPT-to-MBR conversion. Thus, you're not really using your EFI/UEFI firmware as such, so the preceding references may seem of only peripheral interest -- but your firmware is an EFI, not a BIOS, and this fact means that you're dealing with EFI issues even when you boot in BIOS/CSM/legacy mode. If I'm right, the fix to your specific problem is to use FixParts (part of the gdisk package in Ubuntu) to remove the stray GPT data. See here for more information:

Unable to recognize and create partitions for Ubuntu Installation on Dell Inspiron 15R 5520

  • I cannot vote up due to lack of reputation...Thanks for help...But how to use fixparts..can I use it in windows...My windows was installed in legacy mode...Can I convert my existing windows from MBR to GPT? Please make it simple... – nabin May 11 '15 at 5:42
  • Click the FixParts link in the answer for operating instructions. Converting from MBR to GPT is relatively easy, but that would require converting Windows from BIOS to EFI booting, and that's harder. (It's possible, but harder. I used to have a site with instructions bookmarked, but that site's gone away.) – Rod Smith May 11 '15 at 13:08

I have Ubuntu 15.04 running alongside Windows 8.1 on a newish Asus laptop that has UEFI.

Windows was there first and basically I had to do two things before I could add Ubuntu. First turn off UEFI in the BIOS. BIOSes vary and you may have to hunt around for the settings - meaning 1) google for the information but 2) drop into the BIOS and look around carefully.

Second, I don't like the Windows Disk Mgmt application for partitioning. For one, it'll show you less space than you have because it operates within the context of a running system (not a separate boot) and so it can't move, say, the pagefile limiting the amount of space you get.

So the best, imo, partition manager I've used is gparted:


You'll have to download and burn it to a writeable disk and then boot into that - and to do this successfully, you'll probably have to have turned off UEFI first hence that was #1 above.

Using gparted is very nice. It has a GUI interface and you can repartition simply by dragging sliders. Actually performing the repartition is a separate operation so you have time to look it over and feel comfortable with the process. Beyond that, I'd refer you to reading gparted documentation and simply playing with it since, short of the actual repartition operation, you haven't made any lasting changes.

Gparted has been around a long time, is current, and has a large community.

This leaves grub as the master boot manager which if you're unfamiliar with Linux you may be uncomfortable with but I find that it works fine.


You can use the Wubi Method Of Installation like this.

  1. Open the downloaded ISO file.
  2. Run Wubi.exe.
  3. Select the relevant options on the Ubuntu Installer Window that open.
  4. Select "Reboot Now" and Click Finish.

For more details visit this link.

  • Please copy-paste the relevant portion from the link giving teh reference of the source.. – heemayl Aug 11 '15 at 20:32
  • 2
    This suggests using Wubi, which according to at least one comment, will not work. Also, as @heemayl said, you should include the essential information from the link in your answer. – RolandiXor Aug 12 '15 at 2:44
  • you can suggest links in comment box – Prashant Chikhalkar Aug 12 '15 at 5:58

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