I have the F5U103v. That is a USB-to-serial adapter too. If you use "Everest home or corporate" software and connect your hardware, although you have a driver error, Everest will indicate to you (in devices/USB devices) the true hardware manufacturer. In this case "Prolific Technology Inc." and not "Belkin".

There is a link for my case and probably yours, but if it doesn't run, use Everest to locate the real manufacturer:

http://www.prolific.com.tw/eng/Download-2.asp?ID=17

And click on "PL-2303 USB to Serial Bridge Controller" /software and drivers. There is support for all Windows OSes, 32 and 64-bit, Windows 7 included.

This same link could help Mac users. Click on "User Manual" for Linux users.

(The "PL-2303" reference is the hardware ID that is located in "Device properties/ Device ID" on Everest software).

Always use this software for locate drivers for your new hardware devices.

Update: The site is now down, but through google cache you can still reach the downloads. Direct links: google cache

windows driver installer - mac driver installer

If your trying Windows 7 or Vista 64bit, you'll find Belkin don't have 64bit drivers. However, Belkin don't make the drivers anyway. You can checkout this blog post on how to get it working under 64bit Windows: http://www.clearchain.com/blog/posts/how-to-use-a-belkin-f5u409f5u409-cu-usb-to-pda-serial-converter-in-visawindows-7-64bit-mac-osx-10