I had this problem on an E6400 I purchased from eBay. Ugly. I could boot the machine into Windows 7 without any issues. However, the BIOS was locked. I contacted the folks and Mastermind IT and paid them $20.00 via PayPal. Within minutes they sent me a "master" password that unlocked the machine. It worked and I can change the BIOS now.
Note that I submitted the form at 11:00 PM on a Friday night. The service might be a bot though.