Seems that your device use an internal USB-RS232 converter.
If you use VISA-Close after using the COM port, your port should be free again for other resources. What version of VISA are you using?
Next thing is the USB driver of your device. I assume it uses the standard driver of the chip manufacturer. Maybe there is an update too.
However, if you succeed in Hyperterminal (so your serial settings baudrate,data/stop-bits, parity... protocol is right) but not with Labview, the most common pitfalls I come along are:
1. Termination character after sending the command. (In Hyperterminal you hit Enter, sa you need to add a carriage-return to your string. Have a look in the documentation of your device, what termination it use.
2. The VISA-Read has also the capability to use a termination character, so if you haven't disabled it, you are not always reading all data from the buffer.
I agree with Henrik,
I doubt that you need additional drivers for Labview. If you can get it working using HyperTerminal, then it should also work using Labview as long as the ports are configured the same. And as Henrik mentionned, the most common mistake is forgetting the end of line or return character (\n or \r\n).
Don't worry about the 'Direct to Comx'. If Hyperterminal is showing your new com port, then that's all right.
When do this test, do you have a loopback on the serial port and is it wired correctly? You need to jumper pin 2 to 3 if you have a db9 connector.