I wanted to setup a dual boot for Windows 7 and CentOS 7I had a Windows 7 machine with 500GB disk.  I shrank the Windows partition to provide space for CentOS 7 (roughly 230GB).  I created a USB CentOS 7 netinstall stick and booted from that. I ran the install configured as best I knew to install CentOS 7 into the free space (rather than over the whole disk).  I did the net install and all seemed to go well but when it rebooted I was back into Windows and can't get into CentOS.  I've rebooted from the USB and tried to fix the situation (carefully) using cfdisk, e.g. selecting what I believe is the CentOS boot partition but it reports missing operating system.  Also cfdisk says it can't reread the partition table when I write it with CentOS boot but starting cfdisk again seems to show the flag has been set.  Currently the USB CentOS 7 netinstall shows me the following partitions on the disk:## DATA  /home 168GB centos-home  ## SYSTEM  /boot 500MB sda3  / 51GB centos-root  swap 3.85GB centos-swap  The other Windows partitions are:ntfs 100MB sda1  ntfs 253GB sda2This looks ok BUT when I go into CentOS 7 Installation again it is telling me I have to create mount points for the root partition.  I didn't do this originally as I thought it would be done automatically when I clicked Click here to create them automatically for the disk setup the first time I installed.And the partition table accessed using cfdisk from Rescue a CentOS system... looks like this:Unusable 1MB  sda1 Primary ntfs 105MB    sda2 Primary ntfs 265GB  sda3 Boot Primary xfs 525MB    sda5 NC Logical LVM2_member 235GB  Logical Free space 0.03MBAs mentioned, when I try to boot with this configuration I get missing operating system. If I change the boot flag back to sda1 then it boots into Windows 7 fine. UPDATE #1I (re)installed grub2 using grub2-install from netinstall on /dev/sda and now when I boot from the disk I get the grub prompt. I can using it to chain load into Windows. However, when I try to boot into CentOS 7 I get some sort of trace/dump.I used:linux  (hd0,msdos3)/vmlinuz-3... root=/dev/sda3initrd (hd0,msdos3/initrd-plymouth...bootNOTE: I believe linux is the primary boot partition for CentOSTrying the above just crashes.UPDATE #2I installed NTFS-3G and NTFSPROGS using yum from the EPEL repository.I ran grub2-mkconfig -o /boot/grub2/grub.cfg and then rebooted to find Windows 7 (Loader) in the boot menu. But when I choose it I get:error: no such device 978778...error: hd1 cannot get C/H/S values....which doesn't sound very good at all, but at least some progress.I should also say that I now have CentOS 7 only on the internal drive and I'm working on this drive as an external USB drive (hence /dev/sdb).Can someone please help me to get Windows to boot?  I have a Unix background but mostly use Mac OS X.  I always come unstuck on setting up Windows and Linux dual boot.Finally, I have CentOS 6.5 system running fine on another machine, as well as my Mac.
Installed Centos 7 after Windows and can't boot into CentOS
boot;grub2;dual boot;boot loader