On some PCs after installing ISE (5.1i/5.2i/6.1i/6.2i/6.3i/7.1i) and loading the MultiLINX drivers, other USB devices that use the USB ports on the PC become unknown devices and are nonfunctional.
If the MultiLINX cable is not being used, the work-around is to install ISE without the MultiLINX driver. By default the MultiLINX driver is no longer automatically installed as Xilinx announced in May 2005 that the MultiLINX download cable will be discontinued. 7.1i iMPACT will be the last iMPACT software release to support the MultiLINX Cable, as described in the Product Discontinuation Notice: http://www.xilinx.com/bvdocs/notifications/xcn05010.pdf.
To correct the problem for an existing ISE install, perform the following steps:
1. Uninstall the ISE design tools.
2. Using Windows Explorer, browse to the "<Windows directory>\system32\drivers directory", and delete the "mltlnx.sys" and "mlnxfltr.sys" files.
3. Use the Window's Device Manager to remove all USB devices and the USB root hubs.
4. Reboot the PC.
5. After the reboot, the Hardware Wizard should automatically recognize the existing USB ports and load the correct drivers. However, in some cases, you might need to reinstall the drivers that came with your USB device. If Windows does not automatically detect the devices, use the "Add New Hardware" feature in the control panel to find the USB devices.
6. Reinstall ISE, deselecting the MultiLINX drivers during the install process.
7. Reboot the PC. All USB devices on the USB ports should now work.
NOTE: To use the MultiLINX cable with iMPACT, you must install the MultiLINX driver. This problem affects other devices using the USB ports on the PC, but it does not affect MultiLINX cable operations.