@GisMan, we need more information to troubleshoot this:
1. Open a Powershell prompt on the target machine as an administrator, issue this command, and provide a screenshot of the output:
Get-CimInstance -Class Win32_PerfFormattedData_PerfDisk_LogicalDisk | Select-Object Name, FreeMegabytes
2. Open Windows Explorer and take a screenshot of the disk in question under "This PC" > "Devices and drives". For example:
Josh