problem starting my laptop + trying to get back to windows 7

Hello,
First time using forum, but I'll skip the intro and get to why I'm posting

I've bought an alienware m17xr4 with windows 7. When I got it I upgraded it to windows 8 but found it had a few issues, and decided to go back to windows 7.

That's when the problems began. Windows 7 will not install because when I put in the win 7 CD and reboot to attempt the installation it claims there are no partitions, no drivers. The only thing it does see are drives X (for booting) and the CD drive itself, both of which are 'incompatible'.
I've done a check on the hard drive and it's healthy. No problems whatsoever. It's almost as if the C drive only exists when it's started up and at no other time.

Now I've got a problem with booting up windows 8 because I tried figuring out how to intall windows 7 (kind of my fault there). It just says "No operating system detected. Try taking out all devices without an operating system".

Can anyone give a hand? I've called tech support but they haven't answered yet. If they do I'll let you guys know.

 

Check in your bios for if the laptop is set to RAID mode.

Also check the HDD is listed in the bios it might have failed.

 

I've checked the bios. It's set to RAID mode and the HDD is listed (as "Fixed HDD").
I've run the diagnostic using boot options and it seems everything is working fine...

Is there any way I can find the hard drive and format it?

 

You need to change it to AHCI in the bios since you don't have the raid drivers.

 

Hi, thanks for the reply. How exactly do I do that? I don't want to change anything else by mistake. Is there a guide you can link me to please?

 

Go to BIOS, then choose Advanced in main menu, you will see SATA operation currently set to RAID. Just press Enter and choose AHCI, agree you are fine with the changes and press F10 to save changes and exit. If you changed to UEFI boot when installing Windows 8, just go to Exit in main menu and choose Restore defaults and then change to AHCI, since default will revert SATA operation to RAID. When you boot the next time to your recovery media, it will 'see' your HDD.

 

Right, I found the issue.

Because I've got a hard drive that is being accelerated by an SSD, then on start-up windows does not detect this - that's why the hard drive was "no existent" for the whole start-up process.

What i did was, immediately when the laptop booted, before it gets to the alienware logo, I pressed "Ctrl-I" which took me to the RAID acceleration config. Go into option 5, and take off the acceleration by pressing "r". Agree to change the setting.

So now when I put in the disk to install windows 7 it actually sees the partitions, rather then thinking there's nothing there.

Thanks for all your help guys! I've been trying to figure out how to do since for about 4 days straight!