I have a HP -15 Laptop that always locks up during windows 7 start up. . The Screen locks up and a ring of "hazy"color circles the windows 7 logo. I tried a new hard drive and same thing happens? Since the new hard drive didn't fix it then that should be an excellent clue but I haven't the knowledge in troubleshooting. Any help will be appreciated. I realize that I.m working on a outdated Lap top but I want to learn how to repair.Dennis