This will happen if the Wave driver is not installed, has become corrupted, or if there is a hardware problem that is preventing the driver from loading. If the Wave Driver has not been installed, install it from the Pro Tools LE CD ROM. If the wavedriver has been installed and it has been corrupted search and remove the digidesigndalwdm.inf file. In order to locate this file, you must have "Show all files" enabled in the My Computer > View > Folder Options > View tab. Once you have located this file, put it in the Recycle Bin, empty the bin and restart Windows. Upon restarting, Windows should detect new hardware, launch the Hardware Setup Wizard and prompt you to locate the proper drivers.-If you have a hardware conflict that you cannot resolve contact Tech Support.