Inspiron 15R N5110 boot problem.

Hello, I'm having an issue with a laptop and hopefully you guys can help. The laptop in question is a Inspiron 15r n5110 according to the dell support site after putting in the service tag. I believe it was bought in Nov or Dec of 2011, but it belongs to my sister-in-law so I'm not 100% certain. It is out of warranty so that option is out. 

Anyways, on to the problem, it won't boot into windows. It will POST, but after that it shows the info on the PCIe controller. I was originally thinking the hard drive was bad, but the dell diagnostics loads fine and shows no problems at all. All the cabling, memory, proc, hd, etc shows perfectly normal. I'm able to boot into another OS from a thumb drive and everything, including the hd is accessable and works fine. I thought that it was a bad motherboard, but I would think there would be intermittent problems accessing the hd or that the diagnostics would show something. I've tried using the W7 dvd to repair the OS and even reinstalled the OS. That also worked fine, the installation detected the hd, formatted it, and said it installed, but when it went to restart to finish the installation, it just goes badk to that screen. If anybody's had anything similar or has any idea as to what's happening here or how to fix it I'd appreciate it. Even if its bad news, I'd still just like to know whats wrong with it since from everything I can tell...there should be no issue.

Thanks again for any help. I'll upload a pic of the scree I'm talking about.