I want to use one keyboard and one mouse to control 3 computers, with a combination of operating systems: Windows 7, Vista, XP. The KVM is a 4 port with PS2. The computers are either PS2 or USB, with at least one having only USB. For the USB, I've got a "T cable" that is USB on all 3 ends. I plug the base into the computer with only USB. I put PS2 adapters on the other 2 ends of the T and plug one into the first PS2 of the B terminals of the switch and plug the other into the second B terminal. When I use the switch, the video works fine. But the mouse and keyboard don't work. On the computer, when I look at the USB ports under Devices, there's an unrecognized USB port. Obviously, the computer is having a driver problem. Can the Windows driver gurus help me? Duane G. Leet, PhD 45 years experience in technology

Hi, Please contact the manufacturer to check if the KVM switch is compatible with Windows 7 and get the latest version of the driver to test. I also would like to suggest the following to have a check: 1. Boot the system in Safe Mode and Clean Boot to check if it works properly. 2. You may also reinstall USB controllers as below: Reinstall USB controllers ==================== Note: If you are using a USB mouse, please follow the "Use the Keyboard" steps to reinstall USB controllers. Windows 7 will reinstall all controllers automatically after restarting your computer. Use the Mouse -------------- First, please disconnect all USB devices and then perform the following steps: 1. Click "Start", type "Device Manager" (without the quote) in the Search bar and press "Enter". Click Continue if necessary. 2. In Device Manager, double click to expand "Universal Serial Bus controllers", right click on the "Host Controller", click "Uninstall" and click "OK". 3. Repeat the step 2 to uninstall all items under "Universal Serial Bus controllers". Then, restart your computer and Windows will reinstall all USB controllers automatically. Use the Keyboard ----------------- First, please disconnect all USB devices. Then, go through the following steps: 1. Press "Ctrl + Esc" to open the Start Menu. 2. Type Device Manager in the Search bar and press "Enter". Click Continue if necessary. 3. In Device Manger, press Tab and use "Up" and "Down" to move the highlight to "Universal Serial Bus Controllers". 4. Press "Right" and expand it. 5. Press "Down" to move to the first item and press "Delete" to remove it. 6. Repeat the step 5 and uninstall all items under "Universal Serial Bus Controllers". For more information, please refer to the following link: General troubleshooting steps for USB device related problems Regards, Sabrina Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.