[Troubleshooting] Data disks and partitions can't be accessed/missing after updating to Windows 10 Anniversary Update / Redstone 1 edition (build 14393).
LastUpdate : Wed, 10 May 2017
Answer
Please follow the instructions shown in the attachment file to troubleshoot the problem.
Troubleshooting Methods:
1. Get the latest Windows Update.
2. Reset the disk drive letter.
3. Roll back to previous Windows 10 build and perform the update once again.