Blue screen occurs whenever i try to boot my PC or try to format and install the OS. i tried to recover the pc using system restore or the system restore drive in the PC but the same blue screen error occurs and my system crashes. 1. I was trying to defragment my registry (need to restart) 2. When the pc restarted the blure screen error poped when the starting windows logo was gone. 3. The blue screen error occurs only after the windows is loading logo or windows is starting logo is disappeared. How do i format the hardrive and install the windows again. i cant restore i cant format i can do nothing. I am using windows 7 Ultimate RC official version. Thank You

Rohit - First off - defragging the registry = BAD idea. VERY bad idea. Most registry tools available on the market are NOT ready for Windows 7 - yet. That would be any tool designed to "clean" or "defrag" or otherwise manipulate the registry. Secondly... Now that you've trashed the registry... About the only thing I can suggest would be to do an "in place upgrade" - meaning you insert the DVD into the optical drive and booting from the DVD drive. When Windows 7's Installer loads, you'll be doing an installation on top of your existing Windows 7 installation. This will have the effect of resetting your Windows 7 installation to it's default settings. Your data and programs will NOT be touched - they'll still be there. You will need your product key and you'll need to activate Windows again. You'll also need to visit Windows Update again.