If you look in your 'Device Manager' do you see the USB1 cable? (With no yellow exclamation mark)
If so, can you 'assign' a COM Port number to it?
FreeSCAN has a great function to check com ports.
BEFORE! you plug in your cable do the following:
.At the top, under 'SCANNER'
.. Select 'CONTROL SCANNER'
...Select 'COM Port Setup'
....Click on the dropdown box for 'Port #' and note any ports there.
..... Then, plug in your USB1 cable and click 'REFRESH'
..... Then click on the dropdown box again.
..... You should see one more port than before. If not, your cable 'may' be bad.
If FreeSCAN does see your cable, once it's connected to your BCD396T you can click on 'TEST' and it will tell you what kind of scanner is connected.
(If your cable AND scanner connector are good. One of my 396T's developed a problem with the connector and needed repairs.)
If you do see your cable show up and it still doesn't work:
Go into 'Device Manager' for the USB1 cable, 'PORT Settings', 'Advanced' and check to see which COM port is assigned. (You may have to change it.)
then read about the Prolific driver issues below.
It's a long story, but Prolific has added some code in their drivers so that only real Prolific devices will work.
That may show 'Error Code 10' in 'Device Manager'.
Review this thread. (If you have a genuine Uniden USB1 cable, you shouldn't have these issues.)
WARNING: New Prolific drivers for Win 7
And this post from another thread.
Before you buy the USB-1 cable
If your problem is that your PC isn't even seeing your USB1 cable, that's another problem.