VB6 issue is the fault of Microsoft's programmers, not the application programmers-it never occurred to the idiots at Microsoft that people might install old programs). Since I don't use very many VB apps (my PIM is the only one I use daily), I don't worry about it too much, but I definitely prefer to have the correct and latest entries and files, and I don't like them getting damaged by incompetent programmers (the VB5 vs. Any given application might not be affected by earlier bugs, or you might not notice in casual testing. Later VB releases and service packs have various bug fixes and improvements over earlier versions. I remember someone said that they didn't notice downgraded registry entries causing a problem.
The damage is done at installation time, and the earlier software should continue to work. It's not necessary to uninstall earlier software. It probably fixes all recent giveaway damage, but I would have to compare the earlier installation traces with the current, which I won't have time to do until later. This definitely fixes most of the recent damage (on my system, it even fixed another long-standing common file incorrectly placed in an application folder). Different VB applications affect different registry entries and VB common files.
#19, hamstergirl4444, #38, joe, yes, this will fix most or all of the damage done by PD Particles, PDF to Word, and PDF to HTML.