Hello James Anderson,
Thank you for posting in Q&A forum.
Here are a few possibilities and steps you can take to investigate further:
- BitLocker is a common encryption tool in Windows. To check if BitLocker is enabled, go to Control Panel > System and Security > BitLocker Drive Encryption. If BitLocker is on, it will show the status here
- Sometimes, third-party software can encrypt files. Check if any encryption software is installed on your device. You can do this by going to Settings > Apps and looking through the list of installed programs.
- Some malwares can encrypt files as part of a ransomware attack. Run a full system scan using Windows Defender or another reputable antivirus program to rule out this possibility.
I hope the information above is helpful.
If you have any questions or concerns, please feel free to let us know.
Best Regards,
Daisy Zhou
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