There are a number of thread here on this and related topics - I have read them and followed the various suggestions etc. Nothing has altered my situation:
I have just acquired a laptop to use for programming the Arduino Nano. The laptop is a Toshiba Satellite L500-1DT running 64-bit Windows 7 Home Premium Edition.
I installed the latest Arduino IDE and during the install it indicated it was installing drivers. However, when opening the Windows Device Manager (hidden items) there are no serial (COM1 etc) ports listed, they are not even greyed out. Connecting the known working Nano via a known, working USB cable nothing changes, no COM ports. (I know it's all working as I can connect it using an old WinXP Dell laptop).
I have found and installed the CH341SER program, searched all Toshiba support (such as it is) and I am going nowhere. I have looked in the Arduino install files and found that the Nano is not specifically mentioned, not even under the old drivers section.
Just to add to my situation, I can only communicate with you while I am at home and the Nano is fixed to my model railway board at the club 5 miles away where there is no internet connection. So suggestions to try something using the board might take a while :)
However, I suspect the problem is related to driver installation so it might be fixable without the board being connected.
What can you suggest next?