I had the following partition organization
Disk 1 (HD 500GB)
100MB (Windows recovery partition) primary
100GB (Windows partitions) primary
Extended Partition:
- 100GB ext4 linux partition (/home) 
- 300GB NTFS partition (data partition) 
Disk 2 (SSD 32GB)
32GB ext4 linux parition (/)
GRUB is in the SSD, so after installing windows 10, GRUB was working fine. But then, when I tried to boot Ubuntu, it gave me a message saying it couldn't mount my /home partition.
Here's my fdisk -l output
Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x0006ca4d
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      206847      102400    7  HPFS/NTFS/exFAT
/dev/sda2          206848   208795647   104294400    7  HPFS/NTFS/exFAT
/dev/sda3       208795648   209717247      460800   27  Hidden NTFS WinRE
/dev/sda4       209719294   976768064   383524385+   f  W95 Ext'd (LBA)
Partition 4 does not start on physical sector boundary.
/dev/sda5       422156133   976768064   277305966    7  HPFS/NTFS/exFAT
Partition 5 does not start on physical sector boundary.
Disk /dev/sdb: 32.0 GB, 32017047552 bytes
255 heads, 63 sectors/track, 3892 cylinders, total 62533296 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e8e86
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    62531583    31264768   83  Linux
 
     
    