Hello all,
I am using currently windows 10 on my dell 3000 series laptop with Intel M3 processor, 4GB RAM and 500GB HD. I want to install Linux along with windows 10 without formatting my hard disk, and then installing again everything. I tried but every time I stuck with boot manager as it does not shows entry of windows. So I want someone to help me in clean installation of Linux without loosing my data.
Thank you & Regards
Shubham
can you provide some more information about what you have tried previously so we don’t end up repeating something that hasn’t worked?
Here are the steps I followed.
There is one more issue I cant access the windows partition from Linux after following these steps.
Thank you
it has been a while since i have dual booted myself, but have read several times that this is due to a windows fastboot setting in bios/uefi. having that running shuts windows down in a “dirty” state that won’t let linux access it. if you disable that setting, i believe you will be able to deal with this particular issue. hopefully 
apologies for taking these out of order. i missed this when i read through too quickly. have you tried sudo update grub to see if that will list windows for you? i remember when i added a second ubuntu partition (and eventually a 3rd with debian) that they weren’t always properly listed until after i did the grub update.
Okay I will try with that and will get back to you.
Thank You cordx
I tried but every time I stuck with boot manager as it does not shows entry of windows.
The 3000 series is still a current model, I’m assuming that this lappie was installed in esp and used GPT partition tables…?
Look in the BIOS, turn on your lappie and press F2 key repeatedly to enter.
Look for “General” and then the third item on this list is “Boot Sequence”.
There should be TWO entries Windows first and the Linux entry underneath. If not the esp entry has been removed or corrupted.
Can you access your Linux OS…?
Open a terminal and run the following commands as root
parted
type “print” after (parted) prompt (copy the print out from the terminal to a text file)
Parted will also show Windows partitions if they are present.
I’m unable make an opinion, until you answer these rudimentary questions and other once you supplied the print out of parted and efibootmgr -v.
I’m not sure, but maybe this me help you, last post:
If you start from scratch do this:
Edit
You can also install Linux before Windows, in this case better to prepare boot/efi partition (fat32) manually too. If Linux is the first installed you will need to work on the boot loader after installing Windows because Windows boot loader overwrites GRUB2
If already Linux installed and GRUB2 does’nt show Windows you can try with the command
sudo update grub
assuming you are on Debian based distro.
If that does’nt solve the issue, reinstall GRUB2 following this procedure (UEFI environment):
https://wiki.ubuntu-it.org/AmministrazioneSistema/Grub/Ripristino/Uefi
(Sorry, Italian page that one)
Alternately, you can add Windows to the GRUB2’s file 40_custom, something like this one:
menuentry “Windows 10” --class windows --class os {
insmod ntfs
search --no-floppy --set=root --fs-uuid 1D584C40586B2873 # uuid, set yours here
ntldr /bootmgr
}
Source: DualBoot/Windows10 - Debian Wiki
Well, the best form is unfortunatelly delete Win 10.Make backup before
in a pendrive ( 32 or 64 Gib ).Buy a second pendrive ( 8 Gib ) is sufficient.
Use Gparted and delete Windows partition, make a partition for Win 10
but NO USE all space available.Now make a second partition for the Linux
and choice EXT4 for she.( the first for Windows choice filesystem NTFS )
Now install FIRST Windows 10, after install your preferred Linux distribuition
The Linux go detect Win 10, and go put in grub.When start PC, you choice
what OS go be used.This is couple complex, but is the best manner ( form ).
What seems to be the problem? Just use a separate hard drive or partition the one you have to make room for Linux. I recommend Ubuntu 18.04 not 18.10. Install Windows 10 first and then install Ubuntu, telling it what partition to use. I have installed Windows and Ubuntu with various versions of these on the same physical drive with two partitions without any problems. Hope this helps.
If Secure Boot is an issue and you want it on, BOTH OSes have to have it on, SO, Install Windows with UEFI enabled (I had to wait 5 minutes before the Windows Install disk would boot to UEFI so that I could do the install of Windows) and then boot to UEFI enabled DVD of Ubuntu (Or any Linux OS) and it will install UEFI AKA Secure Boot on the Linux Partition. The thing is, IF you have only one turned on with UEFI, the Linux partition’s Grub Loader will not see the Windows Partition/Disk
So if you don’t want to use Secure Boot AKA UEFI, BOTH Windows AND Linux need to have UEFI turned off for Linux to see the Windows Partition/Disk.
UEFI should be the default any way. Thanks.
Have you tried change to change the settings from secure boot? If this is on then it will only boot to the OS you have on. You can also change the bios to legacy if you need to do so. You can also use the repair windows option in windows to install. In the recovery option choose the media USB whatever you are using and boot into that - it is very easy to do it that way - I had a guide written somewhere - if I find again I’ll post it
It worked.
Thank you 
Hi mack,
After doing sudo update grub.
I was able to see entry of windows and linux.
Thank you
that’s great to hear
Sudo update grub worked
My BIOS mode is legacy and not UEFI so i am not able to see UEFI firmware settings option.
How should i disable secureboot then?