Installation Reinstall Grub after installing windows Boot from a Live Linux USB drive. You can use any Live Linux distribution for this, such as Ubuntu, Fedora, or Debian. Once you have booted into the Live Linux environment, open a terminal. For example; Ctrl+Alt+T Type the following command to list all the partitions on your system: sudo fdisk -l Identify the partition where your Linux operating system is installed. Note the partition name, for example, /dev/sda1>/code>. Mount the partition with the Linux operating system: sudo mount /dev/sdx1 /mnt Replace /dev/ sdx1 with the actual partition name. Mount other necessary partitions: sudo mount --bind /dev /mnt/dev sudo mount --bind /proc /mnt/proc sudo mount --bind /sys /mnt/sys Chroot into the mounted Linux partition: sudo chroot /mnt Install the Grub bootloader: sudo grub-install /dev/sdx Again, replacing /dev/ sdx with the actual device name of your hard drive. If you have more than one hard drive, make sure to select the one where the Linux operating system is installed. Update the Grub configuration: sudo update-grub Exit the chroot environment: exit Unmount the partitions: sudo umount /mnt/dev sudo umount /mnt/proc sudo umount /mnt/sys sudo umount /mnt Reboot your computer from the terminal. sudo reboot   My System sudo fdisk -l [sudo] password for csr:   Disk /dev/sda: 465.76 GiB, 500107862016 bytes, 976773168 sectors Disk model: Samsung SSD 850   Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 18F7B150-AD7B-4AC1-9864-0391968D7FE3 Device   Start End Sectors Size Type /dev/sda1 4096 1232895 1228800 600M EFI System /dev/sda2 1232896 3330047 2097152 1G Linux filesystem /dev/sda3 3330048 904714755 901384708 429.8G Linux filesystem /dev/sda4  904714756 976768064  72053309  34.4G Linux swap Disk /dev/nvme0n1: 953.87 GiB, 1024209543168 bytes, 2000409264 sectors Disk model: addlink M.2 PCIE G3x4 NVMe Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 753AD7B1-9E5B-4DC8-A1BF-4966F9CA2801 Device   Start End Sectors Size Type /dev/nvme0n1p1 2048 206847 204800 100M EFI System /dev/nvme0n1p2 206848 239615 32768 16M Microsoft reserved /dev/nvme0n1p3 239616 1999320142 1999080527 953.2G Microsoft basic data /dev/nvme0n1p4 1999321088 2000406527 1085440 530M Windows recovery environment Disk /dev/zram0: 8 GiB, 8589934592 bytes, 2097152 sectors Units: sectors of 1 * 4096 = 4096 bytes Sector size (logical/physical): 4096 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk /dev/sdb: 115.69 GiB, 124218507264 bytes, 242614272 sectors Disk model: Ultra Fit Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x0d320863 Device   Boot Start End Sectors Size Id Type /dev/sdb1  * 2048 242548735 242546688 115.7G  7 HPFS/NTFS/exFAT /dev/sdb2 242548736 242614271 65536 32M ef EFI (FAT-12/16/32) mount | grep /dev/sda /dev/sda3 on / type btrfs (rw,relatime,compress=zstd:1,ssd,discard=async,space_cache=v2,subvolid=400,subvol=/@) /dev/sda3 on /home type btrfs (rw,relatime,compress=zstd:1,ssd,discard=async,space_cache=v2,subvolid=399,subvol=/@home) /dev/sda2 on /boot type ext4 (rw,noatime) /dev/sda1 on /boot/efi type vfat (rw,noatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro)