In order to connect to a bluetooth device on the PC, don't you need bluetooth stack software running on the PC.?
You definitely need that, or something like it. While my desktop can use a bluetooth mouse, I have never succeeded in getting it to talk to Arduino. I have three Dell laptops and one Toshiba. All use the Toshiba bluetooth stack, which is a standard Dell driver, and all of them can talk to Arduino. Toshiba Bluetooth stack will not work on my desktop.
Because I previously tried that and the bluetooth stack software does not recognize the HC06 device connected to a USB port via the converter cable.
This is could be because you are trying to use the HC-06 as a master, but I wouldn't expect the HC-05 to work either..
As to which HC06 module is which - master or slave - surely it would be a case of trying each until you find the one that works with the bluetooth device?
No. Or it depends on the bluetooth device and you either get it right first time, or you will never get it right.
If you are quite sure you have an HC-06, it would be much easier to read the data sheet, wherein you will find it is not a master, it is a slave only device. This will save you the trouble of trying anything. If you just think you have an HC-06, which is clearly the case, you can verify that you haven't by sniffing it with something else, hence my previous comments. I say this because I don't believe you can change the name of an HC-06, therefore, if it doesn't tell you it's LINVOR, it isn't one.
I think you are going off on a pointless tangent anyway. If you just want to communicate with a master, it doesn't matter whether it is an HC-05 or HC-06. If you have an HC-05 configured as a master, I don't think that matters either. I only raise this matter because knowing what gear you have is always a good idea, and you surely don't. The only time you actually need an HC-05 is when you want to communicate with a slave device. The main reasons why everybody buys HC-05 is because it is the bleeding obvious, they are priced about the same as an HC-06, and there is less chance of making a mistake. The man most likely to be making a mistake is the man with two HC-06s.