Printer prints more copies than indicated. Driver reinstalled multiple times.

If you don't have a manual, you can find one here

My guess is either on the printer or the driver. Skimming the manual, it doesn't seem that you can set the default number of pages printed per sent print job on the printer, but that is something I would look into. This is a nice office printer, perhaps the printer is set to print multiple copies of everything it is sent. You could determine if it is the printer or driver/computer by printing to it from another computer.

If it is the computer, go into the control panel and select the properties for this printer. In there, check if the number of copies is improperly set to 5. This would happen for every print job sent from this system.

Does it print 5 copies of documents sent from different programs (i.e. Web Page, Word, Excel)? Quite possibly, one time you set it to print 5 copies and that application retained that as default. In that application, rather than clicking "print" click "printer setup" and look through the settings to see if it is requesting multiple copies.

I am 95% sure one of these three solutions will solve your problem.

When you click "File" and "Print", do you see an option to select a printer, and to choose multiple copies? You should!

it sounds like in your printer driver, the number of copies is set to more than 1 page.

go to printer drivers, and look under printing preferences, and look for what themultiple copies are set to.

Try uninstalling the driver and reinstalling it by going to HP's web page. Before doing so, defragment your C drive.

try to reinstall the printer driver software. you can download the latest printer driver software from yout printer manufacturer's web site then restart the computer and printer.

The printer has performed correctly for two days now - first consecutive days since purchase 6 months ago. I did not do or change anything - have no idea why it is printing the correct number of copies now. I am not confident that this will be longlasting, however.

You might be low on toner.

This problem is caused by Mopier Mode being enabled by default. The idea of Mopier Mode is to minimise computer and network traffic by sending only 1 copy to a printer equiped with suitable internal memory. That stored copy is then used to produce the multiple copies. Most HP Laserjets do not have suitable internal memory and so only the one copy sent by the computer gets printed. To disable Mopier Mode:
Click Start
Click Devices and Printers
Right click your Laserjet Printer
Select Printer Properties
Click the Device Settings Tab
Scroll down to the bottom
If necessary, expand Installable Options
Click on Mopier Mode
Select Disable in the selection box that appears
Click Apply
You will now get multiple copies.

Windows may have eaten its baby again- that is, the driver for that printer.
Open the Control Panel, then Printers and Faxes, delete any listing for that model of printer, make sure the printer is on and connected, then reboot your system. This will force Win to 'find' the printer and install an uncorrupted driver for it.
(=Plug and Pray) 

If you cannot print more than 1 copy, click on...

Start -> Control Panel -> Printers -> Right click on HP 1320 printer icon -> Properties -> Device settings -> Disable mopier mode (last option)

This worked for an HP 1300, 1320 and as well as an HP P2015d using the HP 1320 driver.