Thanks. I actually did. They first tried to tell me that product has 30 day warranty etc etc and it has passed. But the level 1 guy asked me that he will listen to my issue.
Actually, he knew that 1603 error means that some old version exists. But, my control panel/add remove programs showed it is gone. Then he tried to do msi fix from Microsoft but when it asked for product key , he put me in touch with level 2 guy.
He immediately knew what is the issue. He remoted to my machine and all he did was remove WD instances from Program Files and from my local settings. And then we reinstalled. Though I am happy with the support, but it seems that 18.104.22.168 version is buggy. Though it says that 22.214.171.124 fixes the uninstall problem, but it is not.
So, for Windows XP SP3, remove all the instances and then reinstall. I honestly feel that this information should have been posted by WDC and now their programmers has to fix their code.
I have Windows 7 and will like to see if it installs there as it is. But, I feel like a Beta Tester for WDC.