Dell Laptop booting automatically into Diagnostics. Please Help!!!

Hi - I just had the same problem today! It's very annoying. Circumstances that led to the problem: I was running Windows 8 and Ubuntu 12.10 on separate partitions in a dual boot mode. Three days ago, I started having issues with Windows 8 so I reinstalled it completely (reformatted the windows partition) without affecting the other partitions. The Windows started running like a charm, but I stoped getting the dual boot option for Ubuntu - my laptop would directly boot into Windows 8. Since I needed my Ubuntu for some development stuff that I am doing, I tried to fix this by getting the dual option back somehow. I used the Ubuntu Boot Repair software, by creating a bootable USB for it, and running from the USB upon reboot. While using the software, there was an option which said "Repair Ubuntu Boot" or something similar. I did it, and it said that the problem have been fixed, and asked me to restart. Upon restart, the computer goes straight into the Diagnostics with three options 1) Test Memory 2) Test System 3) Exit. I did run the two Tests, got nothing for Test Memory but got two errors for Test System (0F00:065D, 0F00:133C). Upon some google search, it seems that the first error is rather concerning and suggests that my Hard Drie has failed. I don't think this is the problem given the circumstances which led to it, and the fact that I get the Diagnostic screen automatically everytime on start, which should be happening even if the hard drive has failed. Also, the bootable USB I created earlier to fix my Ubuntu boot, and which obviously started all the problem, doesn't work anymore i.e. I can't boot using a bootable USB as well, I still get the Diagnostics on restart. I have tried going to the setup and changing the boot order, and using F12 for boot options, nothing works. Please help! System Info: Dell Studio XPS (Laptop) 16 inch, Dual Core, 4GB RAM, 500GB 7200RPM Seagate Hardrive, supposed to be running Windows 8 and Ubuntu. Thank you so much!