>>>>>Well, I have tried it... Success in connection but never success on Disconnect..
>>>>>and I need to disconnect it in file manager!
>>>>
>>>>What return code are you getting when you issue the WNetCancelConnection?
>>>

---

>>>
>>>return 2250
>>>
>>>Thanks for help!
>>
>>That's ERROR_NOT_CONNECTED. Are you passing the right drive specifier?
>

---

>
>hard to understand now, because I can check that drive in file explorer...
>I have written a onall.prg and offall.prg... and try to call it after onall()!

You should use either GetLogicalDrives() or GetLogicalDriveStrings() to determine whether or not a particular drive is in use. I've never received the error you reported when trying to use WNetCancelConnection()/

hth,