Q.I upgraded my PC laptop to Windows 10 and ever since my computer doesn’t have any sound. How do I get my audio back?

A. Upgrading a computer from an older version of Windows can sometimes damage the system’s device drivers, including the one for the sound card. To grab a new copy of the driver software, go to the Start menu’s search box, enter Device Manager and open it when it pops up in the results list.

Next, in the “Sound, video and game controllers” area, look for the name of your computer’s sound card. Depending on your model, you may see hardware from Creative Labs, Intel or another company listed. Click the Driver tab there and choose Update Driver.

Windows should look around and install a new version of the driver. If the system reports that it cannot find a driver for your sound card, go to the support area of the company’s website and see if there is an updated driver there to download.

Uninstalling the driver — and then having Windows 10 reinstall it for you — is another option. Go back to the Device Manager box, right-click the audio driver and choose Uninstall; if you have a touch-screen device, press and hold the driver to get the Uninstall option from the menu. Restart your computer, and Windows will try to reinstall it for you.

If that maneuver fails as well, Microsoft suggests installing the generic High Definition Audio Device driver, which you can choose in the Device Manager when you use the Update Driver option. Instead of letting Windows look for the driver, choose the path that lets you search the computer and pick a driver from a list.

Sound problems in Windows 10 are not uncommon, and Microsoft has prepared a page of resources that includes a series of video tutorials and troubleshooting tools. You can find it all at windows.microsoft.com/support.

Speaking to Siri

Q. I thought Siri on the iPhone was supposed to just answer if you said, “Hey Siri,” but I still have to press the button. Why?

A.Siri, Apple’s virtual assistant software, will respond without you having to hold down the Home button — under certain conditions. If you do not have one of the newest models, (the iPhone 6s or iPhone 6s Plus), you need to have the phone plugged into a power source to summon Siri solely by voice.

The “Hey Siri” option also needs to be enabled on your iPhone. To check in iOS 9, open the Settings icon on the Home screen. On the Settings screen, tap General, then Siri and flip the switch next to allow “Hey Siri.” After a short “Hey Siri” training session, you should be ready to go.

TIP OF THE WEEK The convenience of an e-reader has helped many people fit more books into their lives. For planning purposes, Amazon’s Kindle software can often provide an estimated time it takes to read a particular title. With the book (or sample chapter) open on the screen, select the Menu button and then choose About This Book to see the typical amount of time needed to read the entire thing.

The About This Book option is available on Amazon’s e-reader apps for other mobile devices such as some of its newer Kindle hardware like the Paperwhite model. When you are reading a Kindle book on a touch-screen device, you can tap the screen to cycle through several progress indicators at the bottom of the page, including the percentage of the book read, the number of pages left, the estimated time still needed to finish the chapter or to complete the whole book.