Hello, I'm thinking to install Solus OS alongside my Windows 10 safety with out losing my Data, I have a 100Gb free space where I can install Solus OS. But I don't know the procedures !!

  • Here's what I would do in your situation
    Backup important files
    Double check the important files are backed up
    Triple check the important files are backed up

    1 - boot to a Solus live USB, with GParted, change the flag of the Windows EFI partition to msftdata (right click the partition, select manage flags). Create a 1024MB (525MB is good too) fat32 partition. Create a swap partition (I use 4 - 8 GB). Create an ext4 partition with the rest of the unallocated space. Hit the check to run the commands. Change flag of the newly created fat32 partition to boot, esp.
    2 - Run the installer, install to the swap and ext4 drives you just made. It should select the new fat32 drive for EFI automatically. Make sure it does!!! If so, hit install.
    3 - Update Solus (sudo eopkg up -y)
    4 - In GParted, change windows fat32 partition flag back to boot, esp. (Optional: change flag of Solus EFI partition to msftdata, updates run fine and Windows won't trash it)
    5 - Profit

From past experiences, is better if possible, to install them in separated drives, as windows updates usually breaks boot making solus disappear from boot options.
I recommend to use a virtual machine like virtualbox to avoid possible problems at boot.
The help center have more info that I know of about multibooting solus.
https://help.getsol.us/docs/user/troubleshooting/boot-rescue#multi-booting

Here's what I would do in your situation
Backup important files
Double check the important files are backed up
Triple check the important files are backed up

1 - boot to a Solus live USB, with GParted, change the flag of the Windows EFI partition to msftdata (right click the partition, select manage flags). Create a 1024MB (525MB is good too) fat32 partition. Create a swap partition (I use 4 - 8 GB). Create an ext4 partition with the rest of the unallocated space. Hit the check to run the commands. Change flag of the newly created fat32 partition to boot, esp.
2 - Run the installer, install to the swap and ext4 drives you just made. It should select the new fat32 drive for EFI automatically. Make sure it does!!! If so, hit install.
3 - Update Solus (sudo eopkg up -y)
4 - In GParted, change windows fat32 partition flag back to boot, esp. (Optional: change flag of Solus EFI partition to msftdata, updates run fine and Windows won't trash it)
5 - Profit

@murbert I did everything except touching the Windows EFI partition or change its flag to msftdata, will it cause any issues in the future? also I solved the dual-boot loading following these steps carefully: and everythIing is functioning now with no issues

    As an addendum to this thread, as an experiment, the method I had complete success with installing Solus next to Windows was doing it Window's way: format and size, shrink, and make the partion in Windows dskmgmt (disk management), then go Live and bring the distro to the windows-made (as opposed to gparted-made) partition. Worked well.

    farhatizakaria I did everything except touching the Windows EFI partition or change its flag to msftdata, will it cause any issues in the future?

    My way allows for an EFI partition per installed OS and prevents the second OS installing to the Winbdows boot partition, which is too small. Your way seems to be transferring the windows boot to the Solus boot. I would expect Windows to do bad things to the Linux stuff. Maybe not. Let us know if it does.