If your hard drive is visible in the computer's BIOS but not showing up in Windows Disk Management, it could be due to several reasons:
Uninitialized or unallocated drive: The hard drive might not have been initialized or partitioned. In such cases, it won't appear in Windows Disk Management until you create a partition and format it. You can initialize and create partitions using Disk Management or third-party partitioning tools.
Drive letter conflict: It's possible that the drive letter assigned to the hard drive is conflicting with another device or partition, causing it to be hidden in Disk Management. You can try changing the drive letter assignment for other drives in Disk Management to resolve the conflict.
File system issues: If the file system on the hard drive is corrupted or damaged, Windows may not be able to recognize it in Disk Management. You can try using data recovery software or disk repair tools to fix any file system errors on the drive.
Outdated drivers or incompatible hardware: Ensure that you have the latest drivers installed for your storage controllers or any external enclosures connected to the hard drive. Outdated or incompatible drivers can cause detection issues in Windows.
Faulty or incompatible hardware: There could be compatibility issues between the hard drive and your computer's hardware or firmware. Try connecting the hard drive to a different computer or using a different enclosure (if it's an external drive) to rule out hardware-related problems.
If none of these solutions work, it's recommended to seek professional assistance or contact the hard drive manufacturer's support for further guidance. They may be able to provide specific troubleshooting steps or suggest advanced techniques for resolving the issue.