Compressed (zipped) Folder is invalid or corrupted after downloading from IE8

This problem may occur if HTTP compression is enabled for .ZIP files on the web server that the .ZIP file is downloaded from. When HTTP compression is enabled on the web server, the .ZIP file is encoded before being sent to Internet Explorer. Once the HTTP-compressed .ZIP file is received by the client, Internet Explorer passes the .ZIP file directly to the program configured to un-zip the .ZIP file without first decoding the HTTP compression . Solution :
How to disable HTTP compression (in IE6, 7 and 8) .
1. Open Internet Explorer
2. Go to Tools > Internet Options > Advanced
3. Scroll down to HTTP 1.1 settings, and uncheck the "Use HTTP 1.1"
4. Click OK
This change will fix the issue. Please clear the cache and try in new session