Q: My HP OfficeJet printer and my desktop PC are on a mesh Wi-Fi network. The printer recently stopped receiving printing requests that the PC sent through the Wi-Fi network. But the printer still receives Wi-Fi printing requests sent from my iPhone and laptop PC. What's wrong?

Barney Johnson, Minneapolis

A: Mesh networks use multiple Wi-Fi antennas to blanket a large house with a strong wireless signal. But this convenience comes at a price: Mesh networks are more complicated than those that have a single antenna (usually on your wireless router.)

Because all the antennas in a mesh network talk to each other, they should relay a print request from any computer or phone on the network to a shared printer. But glitches can be caused by:

• Software updates. A recent update to Windows 10 or to PC security software may have scrambled the desktop PC's ability to communicate with the wireless printer. To fix that, use the Microsoft or HP troubleshooting programs for printers (see tinyurl.com/y73ue45y). Or use Windows 10's System Restore to undo recent PC changes (see tinyurl.com/yc4er5lk).

• A Wi-Fi frequency problem. Mesh networks often use two wireless frequencies, 2.4 gigahertz and 5 gigahertz. The 2.4 gigahertz signal reaches farther and penetrates walls better; the 5 gigahertz signal is faster.

But this can lead to problems. If the desktop PC and printer are on different frequencies, your print request won't be received. (To make sure all devices use the same frequency, consult your mesh network setup directions.)

Alternatively, if both PC and printer are using the 5 gigahertz frequency, the signal might be fading out after passing through too many walls or floors. (Reposition the mesh network antennas so Wi-Fi signals pass through fewer obstacles.)

• A mesh network expansion. Each network antenna has a "network name" called an SSID (or Service Set Identifier.) You can even add a secondary SSID to an antenna for special uses, such as restricting Wi-Fi to one frequency. But when you add an SSID, you must provide its name to your main internet router and to every other antenna on the network. If you don't, it could cause network gaps that prevent communication between a computer and a printer.

Q: I plan to upgrade our three PCs from Windows 7 to Windows 10, but I was alarmed by your column on Windows 10's wireless file sharing (see tinyurl.com/y86fu7dh). Can we still share files over a wired home network if we upgrade to Windows 10? Can I share files between Windows 7 and Windows 10 PCs until the upgrade is completed?

David Coats, Minneapolis

A: You can share Windows 10 files over a wired home network as well as a wireless one.

Use the Windows 10 File Explorer to set up a shared folder on one of your PCs. Allow everyone on the wired network to share that folder (see tinyurl.com/y2mr5p6z and scroll down to "Sharing folders using File Explorer.") Then share a link to the folder with your users.

To share files between Windows 7 and Windows 10 PCs during the upgrade process, move the files to a cloud storage account (Dropbox, OneDrive or others), then share a link to those files with all your network users. See tinyurl.com/ybst5fw8 and scroll down to "Method 3. Use cloud drives."

E-mail tech questions to steve.j.alexander@gmail.com or write to Tech Q&A, 650 3rd Av. S., Suite 1300, ­Minneapolis, MN 55488. Include name, city and telephone number.