zip files, and intallation issues

I use MSN and there is issues with opening zip files as attachments. I can open the attachment but when I attempt to unzip it, XP says the file is corrupt. I’m using the built in zip utilties. I use Norton SystemWorks 2003, MSN scans this file with Macaffie AV before I read it. I had the file sent several times and the person send it says the file is working when it was sent. Also the windows installer comes up with a error code 1628 while trying to install a patch for a recently bought game. I’m stumped, system is updated and no apparent OS problems exsist. thanks for your help