I assume, this is not a duplicate post. Please read my findings below before assuming so.
I have gone through several questions over the Internet regarding people complaining that they are not getting GRUB option to get into Ubuntu OS after dual boot installation. But, unfortunately none of the answer worked for me.
I will explain issue that I observed in chronological order.
A month ago, I had set up Windows 7 installation along with RHEL 6.5 in dual boot scheme. RHEL's GRUB used to appear to show me options to select between Windows 7 and RHEL (which means I installed Windows 7 first and later installed RHEL).
Below is/ was my laptop's current partition scheme:
- 100 MB of Windows boot partition.
- 100 GB of partition labelled C (Windows partition).
- 300 GB of partition labelled D (my personal partition dedicated to movies ;) ).
- 75 GB of partition on which RHEL is/ was installed. (Just the root partition).
And, please note that my laptop has BIOS (not UEFI).
I wanted to replace RHEL 6.5 with Ubuntu 14.04 using a bootable USB with the live ISO of Ubuntu and started setup of Ubuntu but Ubuntu's setup showed that:
The computer has currently no detected operating systems
So, I didn't want to take risk of moving into custom partition step. (I guess, there is a module named as "os-prober" which is definitely not working. But it always works with RHEL and that's why I have currently RHEL and Windows 7 installed in dual boot mode in my laptop ).
Clean any invalid GPT leftover in /dev/sda using "sudo fixparts /dev/sda". While performing this step, I accidentally deleted MBR and lost all data stored in my other partitions. :(
Clean shutdown of Windows 7 must be done.
Maximum 4 partitions should be created. Fourth one being the partition dedicated to Ubuntu.
Format fourth partition using GParted.
Tried to fix any boot-loader issue using boot-repair-tool.
Ran "chkdsk" command to make sure there is no error in HDD.
Tried to install Ubuntu using WUBI. Installed successfully, got an option to choose between Windows and Ubuntu. But Ubuntu failed to mount root directory by complaining that no root partition found.
Last one but not the least: Totally cleaned the partitions and performed re-partitioning using GParted as well as windows partitioning tool.
After following Point No. 8, I again tried to setup Ubuntu and Windows 7 as dual boot but the issue remains the same. No OS detected.
Someone might ask me to install ubuntu anyway (custom partition) without caring if it shows that the computer has no detected OS. But, please be informed that I have tried this also. Ubuntu was installed successfully but I didn't get any GRUB menu while rebooting. I had tried to fix this by using boot-repair-tool. But still no GRUB menu was found.
Is there any step I am missing?
Now there is an another story: I tried to have a fedora 20 and Windows 7 dual boot setup. With Fedora I did not get the "No OS detected" message. However, I installed Fedora 20 on the last partition. As you know, Fedora 20 doesn't offer an option as to How and Where to install GRUB. Still, I proceeded, and after successful installation I didn't get any GRUB menu while booting. My laptop went straight into Windows 7. Also tried boot-repair-tool but still no luck.
Let me know if you want any data related to my partition or BIOS. Please don't ask me to create at most 3 partitions, otherwise I have to better live with RHEL in dual boot setup. Please don't ask me to install ubuntu in VM either because I have just 3 GB of RAM.
What else should I do to get Ubuntu dual boot with Win 7?