1. Open WinZip
2. Click 'Option' and pick 'Configuration'
3. Click 'System' and then click the button 'Associations...'
4. Press the little 'v' infront of .CAB (CabView)' so it disapiers
5. Click 'Ok' and 'Ok' in the next window.
All your .cab should now be showen as small cabinets (:cab ) and it should be very easy to figure out if it is .zip or .cab your dealing with..