Hard Disk Monitoring

I often use flash drives and frequently need to eject them. Because HDS is monitoring them windows will not let go: ' The device "generic volume" cannot be stopped because a program is still accessing it.'

How do I tell HDM not to monitor flash drives????

I do not really know what is HDM ...

I can confirm Hard Disk Sentinel does NOT effect this behaviour. Hard Disk Sentinel attempts to detect the status and also display the used / free space but does not lock the device.
If you receive the "device cannot be stopped" message, it is surely related to an other application which may have open file(s)/folder(s) on the device.
Typical is antivirus software (which may perform a scan on the removable device), indexing service and so.

You may try the Configuration -> Disk Control -> Disable detection of USB and SCSI drives option anyway.
Generally it designed for very old card readers and pendrives which may respond very slowly: if this option enabled, Hard Disk Sentinel will not attempt special detection methods, just basic detection - but this may result that some devices may will also have no status information displayed.

Anyway, I'd suggest to use Report menu -> Send test report to developer option when the appropriate flash drive(s) connected, as then it is possible to check the current situation, verify the USB controller and so - which may affect the operation of the flash drive in general.