A tale of two CS4s

I have windows vista and, unbeknownst to me, it installed the 32 bit as well as the 64 bit. When I did the first install, I had problem and was forced to uninstall. I then uninstalled CS3 trail, reinstalled CS4 and everything seemed good….

Until I started to install the plug-ins (Topaz, virtual photographer). If I run the 32 bit version they will run. IF I run the 64 bit they do not. Is the problem the fact that they don’t run on 64 bit, or is the problem that things are goofed up having two different versions?

Also, bridge will default to the 64 bit version and I do not know how to get the option of opening the 32 bit version. Any ideas?

Also, I do no know how to tell from a running program (cs4) if it is running the 32 or 64 bit version. How does one tell?

While we are on the subject, how do I get the "OPEN IN" in bridge to open and NEF (NIKON RAW) in my NX CAPTURE software?

This is my first foray into photoshop, (besides the trial i downloaded a few weeks ago) and I am enjoying it, even though there is a bit of a learning curve.