I am sincerely seeking your help on the matter below.
My desktop configuration is as under:
CPU: Intel I7 3700
Motherboard: Gigabyte H77 DS3H
RAM: 24 GB
OS: Windows 7 64Bit
Drives: 2 SATA Hard Drives
Currently, the OS is on a SATA hard drive. I am planning to install a SSD (OCZ Vertex 3 120 GB) on which some special software (and not the OS) will be loaded. The OS will continue to remain on the HD.
My PC is currently working in IDE mode. I want to run the drives in AHCI mode as OCZ recommends it. I am not sure whether the AHCI driver is installed, though, as the AHCI driver does not show up in the 'Controller' device manager. If I want to install the 'Intel SATA Preinstall driver (for AHCI/RAID mode) available on Gigabyte's website, do I need to reinstall the OS again and install the driver? Can I install the driver without reinstalling the OS? If so, in which folder do I store the driver? Do I need to run the driver software immediately on installation or will the OS autamically do that once I set the AHCI mode in the BIOS?
I have searched google and this forum and the process talks about enabling AHCI (including changing MSAHCI registry)without after OS installation. That aspect seems to be clear. I am however confused on how to install the Intel AHCI driver (as the OS is already installed) and the process of enabling AHCI mode after that.
Good news... I found out what the issue was and it was not related to the bootmgr being missing (although that was what the error message displayed).
My Gigabyte mobo has an option called Hard Drive BBS Priorities. In that, the OS HD was unselected and my other HD was enabled. I simply selected the OS HD, put that as No.1 in Boot Option Priorities (earlier the OS HD was not showing up in Boot Priorities) and boom, my PC booted up properly. My machine is now in AHCI mode I think (it is showing up as that in the BIOS and Msahci start is set to 0)
Hence, altough the error message showed up as bootmgr missing, the bootmgr is perfecly fine. It was just an issue with the OS drive somehow becoming diabled. Wonder why this happened. Why can't Microsoft have a foolproof method of changing IDE/AHCI/RAID modes post OS installation? Why do these issues occur in the first place?
Anyway, all's well that ends well.
As you may have noticed, I am a layman when it comes to computers with zero knowledge. This process has taugth me a thing or two i.e never to fix something that is not broke. Now waiting to install my SSD (without any problems I hope)
Did not notice any difference in speed though with my current HDs.