Thanks guys -you all seem to agree that 7-Zip is the answer. I have downloaded it. But what I am trying to do is unzip a program called XP_CD-DVD-Fix.exe, as my disk drive, which has been perfectly good for a long, long time, has just stopped working. But I can't get this file to unzip whichever unzipper I try to use. I suspect there is something major wrong with my system, as even the new external DVD/CD drive I bought won't work. I should also say that I am trying to go back to XP, as I really hate 7. At the moment I am dualbooting, until I have transferred all my programs into XP. Unfortunately, I can't do this without the disk drive!