Thanks a stack for the input. I don't really want to associate Photoshop with anything other than PSD. I have most other image files associated with the Directory Opus viewer so I can use that from the Desktop, which I use a lot (the desktop). The DO viewer sees any PSD files I have on the desktop too. If I decide to open anything for editing I use Context>OpenWith. This might seem a strange approach to some, but it's the way I've come to prefer doing things - it suits my workflow.
Viewing PSD thumbnails in Explorer isn't my problem. Again, I use Directory Opus for pretty much everything, and it shows PSD thumbnails. (I totally detest Explorer. *G*) In addition to the tutorial you indicated, there are also quite a few freebies out there that make it easy to enable PSD thumbnails in Explorer. I bought the Ardfry codec to be able to view AI and EPS thumbnails.
What I was chasing was/is a solution to being able to view thumbnails OF ANY DESCRIPTION from within Photoshop itself
. Meanwhile ...
I posted earlier about using Libraries to achieve that, but I need to amend that post. Although the Libraries icon exists in the LH panel in the CS4 File Open dialog, clicking on it only takes you to the Libraries folder instead of expanding to the actual libraries as it should. However, this seems to be a fix. In the same dialog panel, you can click on Desktop>User>My Pictures and you will get thumbnails. CS4 then remembers the (last) location opened, and for some reason thereafter File Open shows thumbnails, even if you navigate away from My Pics. There seems to be no need to go back to Desktop>User. Who knows why this works - you do, probably, but I have no idea. For all I know it's associated with the Ardfry codec. I'm just grateful that I've got there in the end!!
I've been in an out of Photoshop 20 times, navigated all over the place, in the last 5 minutes and it's still working for me. But anything can and does change randomly it seems. I am going off now to back up my divine trouble free system!!
This might or might not be relevant to all of the above. To almost totally liberate myself from Windows' clutches I recently moved my User Profile to another drive, then Moved my User files (My Docs, Pics etc) to the root of that drive. (I have hidden my User profile to get it out of the way.) Now I have a nice neat uncluttered folder structure. The by-product is that a lot of other things got tidied up in the process too. e.g. For good measure I uninstalled and reinstalled Photoshop to make sure it would "see" my moved profile correctly. Only one or two minor programs were upset with the changes, and the fixes were minor too.
Cheers and thanks for everyone's patience
Anyway, sorry to ramble on about something so trivial .... I'm an old woman, what can I say??