Can't install properly

[darknezx]

I'm not using pirated cds, well not fully that anyway. My original cd was spoilt, and this will be my 3rd installation if I ever make it work. I am using my backup copy to install, and it was successful once, but now it doesn't even get past 5 %, because every time it's 5% it always prompts cannot find a file, the file it was trying to install before it crashed. I forgot how I got it to work the first time around, and that was after a few tries. Some help please.