CONNECTING PRINTER WITH UBS TO PARALLEL CABLE

HP printers require more control lines than the USB converters provide.  Your only hope for the old printer is to buy a Parallel port PCIe card.  I've worked with several of these converters and NEVER got an HP to work.   Considering the age of the 720C you should be looking at new Windows 7 compatible units.  The "old reliable" may still work OK but it is an "old" unit with the obsolete Parallel port.

John,

A PCI card with a parallel port might be a more stable solution. Do you have an open PCI slot?

Another idea would be a print server with a parallel port. This would require that your router have an open network port. This might be easier to configure than the PCI card.

My workhorse printer is an HP Laserjet 6P (10 years old). It's connected to a Linksys print server with a parallel port connection. Although the print server configuration was a little tricky, it works flawlessly (yes, Win 7 has drivers for this old thing).

I have an old hp  820cse parallel port printer on an old 8400 computer that has windows 7 and it works fine. However--there are no win 7 64 bit drivers for it, only 32 bit, so I can't share the printer with my other computers. I'm using the hp once in a while until the ink runs out and then recycling it.

Don't spend any money on a printer card if you have 64 bit win 7. Just buy a new printer. They are cheap. The expense is in the ink, not the printer.

As I mentioned with the USB adapter, it does not have all the control lines needed by HP's.  It may be recognized but because of the missing control signals it won't print.

We get new PC's with new operating systems and new technology hardware but we forget about also upgrading to new peripherals (e.g. printers) and thus compatibility problems arise.  Such is the case with this "old reliable" printer.