I have a problem with the xilinx 9.1 software and i found this on the xilinx forums.
This is an issue with the Jungo driver used by the Cable on Vista. This issue affects only machines running Microsoft Vista and is resolved in ISE 9.2.02.
How do I update my Xilinx 9.1 to 9.2 to solve this.. Or is there any other solution
From the Start menu, go to Xilinx ISE Design Suite (or Xilinx ISE Webpack) and run the XilinxUpdate. It will connect to Xilinx site and give you the list of available updates for your software. Other way is to register on Xilinx.com (it's free) and then you can download updates for the offline installation.