I was getting the same error:

'1608: Unable to create InstallDevice instance'

I downloaded the isscript.msi and ran it separately (as recommended in the limewire faq) but, still no install.

After seeing this message I moved the 'Program' file to my desktop and deleted it from my C: drive after that the install ran fine. I am running xp pro and I noticed that the 'Program' file only appeared after installing Quicken 99. I kept a backup copy in case quicken might need the file. I suggest everyone else do the same. Truthfully, you could probably put the file back after installation but my morbid curiosity wants to see whats gonna break when it isn't there! hahaha!

M. Burch