You may need to download special usb drivers as described here:
http://www.saris.com/...AQ.aspx#Softwarefaq8 (You would get the drivers from here:
http://www.saris.com/poweragentDownload.aspx)
To update the driver:
- Make sure your Indoor Cycle or PowerTap computer is plugged into a USB port, and the bike computer screen is reading HOST.
- Click on the Start Menu.
- Right-click on My Computer.
- Click on Manage. This will open a Computer Management window.
- In the left panel, click Device Manager.
- In the right panel, right-click on the USB or Serial device that is marked with a yellow question mark or exclamation point.
- Click Update Driver.
- A wizard will open.
- If the wizard first asks whether it can connect to windows update to locate the correct device driver, select "Yes, this time only," and move on to step 11.
- If the option to connect to windows update to locate the correct device driver is not available, you must manually download the drivers.
- Once the drivers have been downloaded, return to the device manager following steps 1-8 above.
- Select "Install from a list or specific location."
- Click Next.
- Select "Search for the best driver in these locations."
- Check "Include this location in the search:"
- Click Browse to navigate to the location on your computer where you saved the driver.
- When the driver is selected, click OK.
- Click Next. This will start the search and install.
- When it is finished, you should have a screen that says the driver was successfully installed.
- Click Finish to close.
- Return to the Device Manager
- Check to see that there is no question mark or exclamation point next to any USB serial device.
- Expand Ports (COM and LPT) by clicking the + to the left.
- In this list, you should see a USB serial port with a COM number next to it. This indicates that the correct driver is installed.
- Your PowerAgent should now recognize and download from the computer.