Did you remove the protective tape from the ink cartridge heads? <grin> Seriously though, what hodmokrin stated above is a very common reason for this problem. I would add that most printers have a way to invoke a built-in self-test printout.
If the printer prints this self-test page correctly, then the problem is not in the printer. Keep in mind this is not the same as the Print Test Page option in Windows. The printer self-test should be able to be performed from the printers button controls without even being hooked by to the printer.
If the self-test also results in a blank page then the problem resides in the printer. In addition to hodmokrin's instructions, also clean the copper/brass print head contacts in the same manner. Finally, if no joy... try a new cartridge.
If the self test page was successful, then proceed to try to print a Test Page from your Printer and Faxes Control Panel Option in Windows: Start->Control Panel->Printers and Faxes->right-click on your printer icon->select Properties->click on the Print Test Page Button. If this produces a good printout, then the problem is in your application (ie: Word or such). If you do not get a good test page, I would recommend uninstalling and reinstalling your printer software.
Good Luck!