Q: We have an HP Officejet 4500 printer, and are able to print wirelessly to it from my HP PC and my wife's Mac. But we can't print wirelessly from our two new iPhone XS models because neither of them recognizes the HP printer. Is the printer installed incorrectly, or is it just too old to work with the iPhones?
--Rudi Gutmann, Minneapolis
A: Your printer, which was introduced in 2010, can't use the newer wireless printing technology built into the iPhones. But you may be able to wirelessly print using other for-pay iPhone apps.
The HP Officejet 4500 was designed to accept wireless printing requests from PCs and Macs that are on the same Wi-Fi network. But it can't accept printing requests from the iPhone's AirPrint wireless printing software, which works either over a home Wi-Fi network or directly between an iPhone and a printer.
Normally, you would turn to an alternative wireless printing method, such as HP's ePrint service (it e-mails documents to the printer) or Google Cloud Print (it sends cloud-stored documents to the printer.) But the Officejet 4500 is just old enough that it isn't compatible with either of them.
That leaves you with third-party iPhone apps that are designed to wirelessly connect to older printers like yours. They include Printer Pro ($7) and PrintCentral Pro ($6), which are available in the Apple App Store.
If you would rather buy another printer, Apple maintains a list of AirPrint-compatible printers from all manufacturers (see tinyurl.com/ou6jobs) .
Q: I'm unable to hear any sound when I try to view video clips or listen to music on my Windows 7 PC from HP. When I hover my mouse pointer over the speaker symbol in the PC's task bar, I get the message "No audio output device is installed." What should I do?
--Keith Knefelkamp, Victoria, Minn.
A: HP said the lack of sound is probably caused by the PC's audio software driver. Software drivers connect programs to the PC's components, such as the speakers.