Vista delivers report results in zip, .gzip and .gz file formats. This compressed file format enables the file to be transferred faster than its expanded format. More information about .gzip files and how to open them can be found on fileinfo.com.
On PC
After downloading on the zip file, use an extractor like 7zip or winzip to open the file (especially important for gz files)
On Mac
Double-click on the file after downloading, and the Mac will automatically unzip the file.