For complex graphics or network use, you'll want at least 2MB and preferably 4MB to handle these resolutions. Confirm that the Device Options tab in the Properties dialog box lists the correct memory settings. If Windows doesn't know about your extra memory, it can't use it. If your printer won't work at all, check to see that cables, power cords, paper trays, and switches are in their proper positions. Next, see if your printer is communicating with your computer.
Many printers have a switch for toggling between online and offline states.
If the trouble persists, turn the printer off and on. It's amazing how often that fixes a problem. Print a test page from the printer's control panel, not from Windows. Next, double-click the Add New Printer icon. The Add New Printer wizard will ask you to select your printer from a list of possible choices.