I own an HTC EVO 4G that's telling me the SD card isn't mounted. Attempts to mount it give me a recommendation to reformat the card. Model: HTC EVO 4G Carrier: Sprint Android version: 2.3.5 Rooted?: No Power: battery approximately 75%, and on AC power Networking status at time of issue: wi-fi on, 3G off, bluetooth off Background data: Enabled Activity: Browsing Google play, installing apps, trying them, and uninstalling them. Free space on phone: Approximately 150MB SD card size: 8GB SD card brand: Samsung SD card class: 2 Free space on SD card: Approximately 4GB Troubleshooting Notes I've browsed to running applications and Force Stopped HTC Sense and hit Home with no change in symptoms. I've rebooted the phone with no change in symptoms. I've removed and reinserted the SD card with no change in symptoms. I've installed the SD card into another phone and the SD card was recognized with no mounting messages. I've installed the SD card into a memory card adapter and installed it into my laptop (Windows XP, SP-3) and the SD card was recognized with no errors. I ran Properties > Tools > Error Checking and no errors were found. Years ago I had the same problem that was solved with no 3rd party software and no SD card reformatting. I'm sorry to say I don't remember what the solution was. I seem to recall it had something to do with deleting or modifying one of the files on the SD Card. Does anyone have any recommendations that haven't been mentioned here already? I'm confident the SD card doesn't require reformatting. Despite the popularity of suggesting spontaneous failure, "sometimes they just go bad" isn't troubleshooting, it's half-ass guessing. Besides, it's been tested in another phone/laptop so we can rule that out. I've read several similar threads on this and other forums, however the one thing they all have in common is "shot-in-the-dark" troubleshooting, no genuine recommendations based on listed symptoms. If you've got some genuine help to give, fire away!