Normally this llb is found at C:\Program Files\National Instruments\Labview 7.1\vi.lib\daq if it isn't there, try to look at National Instruments folder (C:\Program Files\National Instruments) to see if there is another folder named with other version of LabVIEW, for example, LabVIEW 7.0 or 6.1. If you find the llb in this folder, move it to first path I wrote. If don't, you could use the attachment and extract the llb placing it at the first path too.
Even if this procedure doesn't work, what you can do is try to update the driver to a newer version. Please use the link below to download it and then follow the steps at the bottom of the page to install it