Hello Hai,
LabWindow/CVI was created to run on Windows 2000, Windows NT 4.0 SP3, Windows 98 and Window 95. Have you tried installing CVI 5.5 on one of these older operating systems? Conflicts between the installer used in CVI 5.5 and Windows XP could be the cause of the problems you are seeing.
Thanks.
Wendy L
LabWindows/CVI Developer Newsletter