for some reason, I only get PDF thumbnails and PDF preview in the Opus preview pane if I set PDF-Xchange Viewer as standard file handler for PDF -- which so far is ok because I like the PDF-Xchange preview handler more than the one from Adobe.
However, I'd rather have Adobe Acrobat 7 as standard program to open PDF files (if double-clicked), and still keep a) PDF thumbnail generation (by whatever program) and b) PDF-Xchange Viewer as preview handler in Dopus.
Is this possible, and how would I proceed to get there?
It's all controlled by registry settings on the PDF filetype. Usually when you tell one program to take over the filetype it will take over all the functions (double-click, thumbnails, preview), or at least the functions the program in question handles. (Whether the others are left assigned to the previous program or simply broken depends on how 'nice' the program is at merging the filetype settings.)
You could manually edit the registry to combine different settings from different programs, but if you're primarily interested in what happens within Opus then it would probably be easier to assign PDF-XChange Viewer as the default PDF handler, and then, in Opus, use Settings -> File Types -> PDF -> Events -> Left-double-click to assign Acrobat to open the file on double-click. The Events tab is specific to Opus and doesn't modify the system filetypes or registry at all, so overriding the double-click action via that will be least likely to confuse the other programs.
Alternatively, you might be able to have Acrobat as the default PDF handler, and then assign the PDF-XChange viewer via the Opus ActiveX plugin's configuration window, which lets you override which filetypes are assigned to which preview handlers. (This is also an Opus-specific override and won't affect the registry.)
If you want things to work in Explorer as well then editing the registry is the only way to go, however.
Thank you Leo, this is actually the way I'd like it the most (and which I have tried already). For some reason however, PDF preview (this way) did not work, AND I didn't get PDF thumbnails anymore with such a setting.
From your post however I take that it can be done, thus I will have another look into things and check whether I can get it to work.