I've browsed almost all the previous posts on this subject and most of them give the same solutions: get Winrar or Winzip... or something of that sort. I personally am a little paranoid about the wellbeing of my computer and I'd like to get behind the problem as to why it shows this: The Compressed (zipped) Folder is invalid or corrupted. Unzipping with XP worked a couple days ago and starting today, it is giving me that message for many many zips that are most definately not corrupt because they have been tested on other computers that my friends own. I simply click the folder to open the unzipped folder but it gives me that message. If I try to extract that folder, if I extract it to any location on my computer, it tells me that there are no files to extract... what an enigma...

Search google fpr "repair zip files". Mucho info. Rgds

I did what you recommended and all I seem to be getting is links to fix corrupted zip files. My zip files are not corrupt or invalid, my compression program is the one that has the problem because my zip files work wonderfully on Winrar :)

The exact same thing happened to me. A couple of days ago, fine. Today, error. I even tried opening zipped files that had been downloaded and extracted successfully months ago. That lead me to the same conclusion: something messed up with XP's built-in handling of zip files. And very recently. Then I found something. I think it might be a glitch in the latest Symantec Anti-Virus definitions. On a hunch I disabled the realtime protection. On the first try at opening a zip file, I got an error and the usual prompt to report it (which I DID send to MS). Now the zip files open fine. They even still work after re-enabling anti-virus realtime protection, rebooting, etc. So far, so good. Still, that was a strange one...