This is a picture from the device manager:
The arduino:
Operating system information:
I tried to install drivers manually, but had no success.
Please help.
please try to remove and reinstall correct Drivers from your OS
The nano's come with two different usb uart chips, and they make a difference!
The FT232R and the CH340G. Do you know which one your nano has?
The official Arduino nano, made by Gravitech should have the FT232R, original uart.
Many China clones are using the CH340G because it is less expensive.
Some clones (and maybe even Genuine Gravitech Nanos) have counterfeit FTDI chips. At one time, there was an FTDI driver that (intentionally) broke counterfeit FTDI chips; I'm not sure about the current state of that fiasco, across all versions of windows/etc.