I have download the zip file for the 800/900 upgrade twice. Both times when unzipping (with winzip 9.0) I received the following message:-Extracting to "c:unzippedPMDG_737_NEXT_GEN_800_900"Use Path: yes Overlay Files: yesExtracting PMDG_737_800_900.EXEbad CRC 39adb6d2 (should be bab25188)Extracting README.TXTInstallation would not proceed ....... does anyone have any ideas as to what may be going wrong...I use broadband and don't normally get problems and did a clean restart before the second download.Many thanks for any help anyone can offerJohnLondon UK

Thanks PMDG for making a prompt reply to my email.The problem did not appear to be my firewall or antivirus software (both of which are Norton 2004), but the problem did clear when I switched off my anti adware/spyware software (in this case "spybot") The download then performed and installed correctly.JohnLondonUK