Ok here's the problem, I have a Lenovo Thinkcentre M91p desktop which I was preparing to sell, first thing I wanted to do was to erase contents of hard drive first by using Derik's Drive Nuker disc however the problem started when the PC starts it doesn't show the "Lenovo" logo splash screen with the F-12 option to access BIOS, I needed to access bios so I can reboot with the dban disc to erase the hard drive when that option was not available I opened up "msconfig" and made the mistake of changing the system configuration from "Normal start up" to " Selective Startup" with only the " Use original boot configuration" option checked because I thought that would show me the splash screen on start up but, that wasn't the case. After I did that and restarted the PC everything was horrible, not only wasn't I able to see the splash screen but, also Windows wouldn't even load. On start up the PC doesn't show the Lenovo logo splash window, it goes straight to windows but it only shows the pre-screen that pops up before the log-in screen, the one with the background image and the time on the lower left but, that's it....if I click on that window instead of showing me the log-in window where I'm supposed to enter my password it only shows a blue screen. Now I can't access BIOS to fix anything nor get into Windows. I need help please! Any suggestions will be helpful. NOTE: btw, I already attempted a suggestion from another user to disconnect the data cable off the harddrive and restart the computer to see if it would allow me to get into bios but, that didn't work.