I installed Ubuntu version 12.04.3 on my desktop and after that I cannot boot Windows. The computer has two hard disks (one is 2TB, one is 1TB). Before I installed Ubuntu, I have Windows 8.1 installed on the 2TB hard disk. The 1TB hard disk is empty (no partition, no logical drive). I installed Ubuntu in the following steps:
(1) create a Ubuntu 12.04.3 installation DVD
(2) boot from this DVD
(3) Ubuntu installation program shows the following disk partition:
/dev/sda (2 TB disk with Windows 8.1 installed) /dev/sdc (1 TB disk, empty, no partition) /dev/sdb (32 G flash drive)
(4) I created two new partitions on /dev/sdc (1 TB disk):
/dev/sdc1 (ext4 format with 968 GB) /dev/sdc2 (swap, 32G)
(5) I chose to install boot loader on /dev/sdc (1 TB disk)
(6) Everything was very smooth. But after I restarted the computer, there was no Windows boot option. It directly boots to Ubuntu 12.04.3 user loggin screen. Ubuntu still can access Windows 8.1 disk (/dev/sda, 2TB) and I can access all the files there. But I cannot boot Windows 8.1.
(7) If I unplugged the hard disk with Ubuntu installed (i.e. /dev/sdc with 1TB space), the system still cannot boot Windows 8.1. It stops with the "grub" prompt.
Can anyone help with this problem? Thanks.