Since you posted to the Off topic folder, I'll leave it here as I don't believe that your issue has anything to do with Windows Live OneCare.
OneCare has not been updated in many months now and it does nothing to compressed folders in Windows or zip files created by other compression/archive programs. If you have been using the native compression of Windows, compressed folders in Windows Explorer, you should post you issue in one of these forums, depending on your operating system:
Vista: http://social.answers.microsoft.com/Forums/en-US/category/windowsvista
XP: http://social.answers.microsoft.com/Forums/en-US/category/windowsxp
Windows 7: http://social.answers.microsoft.com/Forums/en-US/category/windows7
If you are using a 3rd party tool such as WinZip, you may want to re-install it or contact the manufacturer for support. You may also want to consider installing this free alternative for creating and opening .zip files - http://www.7-zip.org/
-steve
~ Microsoft MVP Windows Live ~ Windows Live OneCare| Live Mesh|MS Security Essentials Forums Moderator ~
