The panic is real when you find your photos mysteriously disappeared from your HTC one, either the photos were mistakenly deleted or the SD card went haywire, three different outcomes are expected.

An online backup saves the day.

In the cloud era, everything's connected. It's actually quite difficult to lose something as precious, as well guarded as the photos archived by your HTC One M9. Thanks to the fierce competition, the predatory marketing from Tech companies like Google, Microsoft or HTC, all spares no efforts to be your silent guardian, your watchful protector. Your entire album may have already been tucked safely away in their server even without your knowing.

To locate an online copy, the Photos app on HTC One M9 is the place to look at, Google's official app will have the auto backup feature turned on if the app were opened at least once, it keeps uploading photos/videos to your Google cloud drive constantly while the device is connected to a Wi-Fi network. But if you actively turned off Google's backup solution, Dropbox, Microsoft SkyDrive are also places you might get pleasantly surprised.

If that whole Celebgate thing doesn't ring a bell, it's actually good practice to keep your auto backup turned on to prevent future devastating files losses.

Without a cloud backup

The photo recovery software we're going to use is computer based, it's available on both Windows and Mac OS, if you're reading this article on your phone, then you need to find yourself a computer to proceed.

• Download Stellar Phoenix photo recovery software. The software is able to recover deleted photos, videos and audio files.
• Photorec is the open source alternative of the photo recovery. It's great at finding deleted photos and is available on multiple platforms – Windows, Mac and Linux. Same as the stellar photo recovery software, it doesn't support mobile platform.
• Take the micro SD card out from your phone and connect it to computer with a MicroSD card adapter or USB Micro SD card reader.
• Run the software, it automatically recognize the One M9's storage and scan for retrievable files, the scanning process will probably be lengthy, the software's hunt will not be limited to those mistakenly deleted files, but all the files that ever existed on the card. During the scanning, retrievable files are categorized and listed by file types and extensions, the files can be previewed, evaluated, before you make the decision to buy the software.
• Recover deleted photos, videos and audio files.

Hopefully at this point you have already been reunited with your lost photos. If not, this is the outcome Three: if the photos were stored and deleted from the HTC One's internal memory, they are gone. But don't be so gloomy, early days my friend, the future is splendid and it's yours to archive, just remember to back up regularly.

Frequently asked questions

What to do to prevent this from ever happening again?

Backup everything is the tried and true motto you should stick to. Backup everything on your laptop and backup everything on the cloud, well maybe selectively on the cloud because it becomes costly after the free storage quota is met. Also, maybe not using a SD card, store important stuff like your photo only on your internal memory. Micro SD cards are known for their notoriously low quality control, the reliability is a real concern.

Why deleted photos can be restored on the memory card?

When a "delete" command is issued by the One M9's operating system, the selected photos weren't necessarily erased or destroyed. The OS merely removes the pointers to these files from the file system. It's like a person's ID is revoked, thought he exists, he's no longer visible in the system's database. To recover the deleted photos, you just need to find them.

Why some of my retrieved photos are partially visible with large grey areas?

While the deleted files weren't immediately destroyed on a HTC One M9, they have been marked as unnecessary files to free up the memory space. If you kept taking photos after the deletion, there's a chance that the new photos will take up the old ones places and make the deleted files irretrievable.

Why photos stored and deleted from the internal memory can't be recovered?

After the ice cream update, android system drops USB mass storage device support for the internal memory because of security issues. The internal memory is no longer accessible to PC software like our photo recovery, it can't be detected by the software while the phone is connected so files deleted from the internal memory, unless being previously uploaded to the cloud, are irretrievable.