Problem interfacing Platform Cable USB DLC9G
It's funny you should ask this. I just managed to successfully install the DLC9G driver for ISE 14.7 Webpack just two days ago onto a Windows 7 Professional 64 bit computer (a painful experience).

There were a couple things I needed to do in order to install the driver:


Despite administrator privileges and performing all installs using "Run as administrator", I kept getting driver installation failures which included an "Access is denied" message. I finally found FIX: Access is denied error while installing software on Windows 7 | 8. Scenario 2 provided the help I needed. This required going to "User Account Control" and setting it to "Never notify" and then rebooting.
The next thing that needed to be done was to manually install the driver. First I went to Device Manager. I then plugged in the DLC9G and noticed the exclamation point over (I believe) "unknown device" (or something similar) located in "Programming cables". At this point, I thought it would be a good idea to right-click over "unknown device" and select "Uninstall". Next I right-clicked over "unknown device" and selected "Update Driver Software...". Next I selected "Browse my computer for driver software". Next I chose "Browse..." and pathed to C:\Xilinx\14.7\ISE_DS\common\bin\nt64  ... I also had "Include subfolders" checked. Clicking on "Next" installed the driver and my DLC9G was working!


The driver I used came with ISE 14.7 Webpack. The path I used above was the path for the default installation. I did not use the User guide (ug344) or the drivers indicated in that guide.

Item 1 above (the fix for the "Access is denied" error) also fixed a problem I was having installing drivers for the Microchip ICD3. 

After correct installation, Device Manager indicated "Xilinx USB Cable" under "Programming Cables". It also indicated "WinDriver" under "Jungo" which previously also indicated "unknown device" (or something similar).