You are not installing the bag properly, most likely. What is the style/type of bag? It should have a letter.
These Chinese-made vacuum cleaners use a hose, which when installed, will lower just inside the vac bag opening. This prevents any debris from escaping, when the machine is turned on. Remove the hose from the machine. Then open the bag compartment and remove the bag frame, which holds the bag. Make sure the bag is installed on the frame properly. There is only one way the bag will fit. Now, reinstall the frame and bag into the vacuum. It should slide down into slot(s). Close the lid. You should be able to look in the hose inlet of the vacuum and see into the bag. If it is not installed properly, you will most likely see part of the bag collar. It will look like a crescent moon. The hose cannot fit in the vacuum, when the bag is like this. If the bag is installed properly, then the hose can be inserted into the vacuum cleaner quite easily.
Also make sure the ends of the bag are tucked into the bag compartment, because they can keep the vacuum from having a good seal if stuck in between the vacuum base and the lid.
This message was modified Oct 23, 2012 by Mike_W