I'm sorry if this is a duplicate post, but honestly, I did Search for "Code 5" and found nothing. I have a HD on an eight year old desktop PC that had an early beta version of Win-7 on it. That old version has already expired. I wanted to boot up with my Windows 7 Ultimate DVD and just do an overlay install. Well, every time I tried to boot the PC from the DVD drive, I got the dreded "Cannot Boot From CD, Code 5" error message. Of course I Googled the problem and found only one fix that I was able to execute. The fix involves running the Setup on the Win-7 DVD from within an earlier version of Windows. The suggested version was Viata, but since I already had an early version of Win-7 on there, I tried that. So far so good. The Setup program informed me that it would put the old OS in a folder called Windows.OLD. I guess that's OK, because I can always delete that later. Eh? This OLD computer may not run Windows 7 Ultimate very well at all, but at least I found a "Work Around" for that nasty Code 5 error message. + Win-7 did get the sound working and set up my wireless N card with no problem. But it doesn't seem to know exactly what to do with my 8 (or maybe 9) year old video card. I can live with 800x600 resolution, for now. It does have one higher res., but the on-screen text is almost unreadable. But for a testing machine, this one is working pretty well. I even got Windows Mail working with a minimum of effort. Cheers Mates!