I replaced a crashed HDD on a friend's Sony VAIO SVE14111ELW with a new Seagate Momentus 320 gb 7200 rmp SATA hard drive (I ordered it bare from Amazon); because the other hdd crashed and my friend doesn't seem to have received any recovery discs and here I am fetching all I need from good ol' Internet.
After installing the new hard drive, I booted-up the laptop and went straight into the BIOS (Insyde H2O), which indicated the hard drive (all 320 gb) was detected and proceeded to install Win 7. I then created the new partition as required, formatted it as NTFS and installed Windows 7.
I installed and updated Windows 7 and the required updates and drivers; the system rebooted fine each time and came back to Windows with no problems. After I was done, I turned-off the laptop and went to lunch. Once I came back, I turned the computer on to install other software and got an "Operating System not found" message after the BIOS screen displayed. I then turned off the computer and F2'd into the BIOS and, without changing any settings, I exited the BIOS and noticed the computer booting into Windows.
This happens consistently - I turn on the computer and get "Operating System not found," or if I turn the computer on, go to the BIOS set-up, do nothing, save and exit then it boots into Windows fine.
I installed GRUB and get the same issue, the SeaTools utility detects the hard drive in Windows, but not outside of it (DOS mode) so I'm unable to run any fixes on whatever could be bad in the hdd.
I searched for the BIOS update, but there seem to be none. Any help is much appreciated.
UPDATE: I installed other HDDs and they work fine, I was likely sold a lemon - thanks for your support.