My printer is printing weird symbols

This can be the result of a corrupted font or a corrupted printer driver. Though it is a bit dated, please use this article to help you troubleshoot the source of the problem (even though you are not using word, it will help.) It may be necessary to reinstall the printer driver.
If you're in xp, you may first wish to try deleting all print jobs and clearing the print spooler cache. See instructions here.
If you need to download the latest printer driver from HP, you can do that by clicking here and choosing your OS. Here's a guide to updating drivers if you want a tutorial for that.
Finally, here are some troubleshooting links that may help in the event that the previous didn't work, or you wish for more detailed instructions.

I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take just a moment to rate this post....thanks!

Is it printing multiple pages with just a line or two of weird symbols? Usually thats a problem with the software. If your using windows go to "start'...then "printers and faxes". It should show the printer your using as the default. (You'll see a little check mark over it). Right click on that printer...go to properties...print test page. If that comes out normal then its not the printer its what your trying to print with it.

Try this:
Click Start, then internet explorer, then tools, then internet options, advanced tab, reset button, a new window appears then reset, close Ok.