Those other PCs/laptops you tried it on were all Vista? Or also XP and Windows 7? Finding another XP computer shouldn't be too difficult.

You might need to install Vista software/drivers for this camcorder if you installed the XP equivalent on your XP system. Did it come with installation instructions and a CD? Did you look at the Samsung site for possible software?

And there's always the option the camcorder is defective.