It will make the conversion to a newer version of LabVIEW easier. If it had been LabVIEW 3.x, you would not be able to directly load the VIs into labVIEW 6 or 7. If all you have is an older version, you'll have to rebuild it at the very least in order to run under WinNT, 2k, or XP. I don't remember at what point NI dropped support for Win 3.x but I do remember that the last version that did had two different application builders. You should also be aware that the first version of LabVIEW that NI officially support for WinXP is version 6.1.