Try downloading the latest drivers from midiman.com Also, make sure you have Windows XP Service Pack 1 (SP1) and install it if you do not:

Right-click on MY COMPUTER, select PROPERTIES.
This will display Microsoft Windows XP Home Edition and on the 2nd line, Service Pack 1 if you have it.
If you do not have it, we recommend you download it at www.microsoft.com This download is 133mb, so we recommend finding a high-speed internet connection and a cd burner for this task, or you can order a CD from Microsoft. Download the 32-bit version, not the 64-bit version. It's best to get the Network install, which contains all of the updates in a single file for burning to CD. The Express install performs the same task, but downloads the data as needed throughout the update and therefore cannot be saved for future use.