Multiple prevhost.exe left running

I'm trying to get PDF thumbs and preview working on Windows 7 and have got frustrated with Adobe and FoxIT and am now trying PDF-Xchange. Things seem to be working okay except when previewing PDF files in Directory Opus every time I preview one I'm left with another instance of prevhost.exe running (visible in task manager) - and they just stay running. When previewing through explorer I get only 2 instances of prevhost.exe and they close down shortly after I shut down explorer. Any ideas??
I'm pretty over this to be honest - thumbs and preview of PDFs really shouldn't be this hard....

They'll probably shut down after 10 minutes. It's normal for COM servers to remain running for a little while in case they can be used again. (OTOH, it could be that they've crashed or something, if they never shut down.)

I don't think FoxIT does PDF thumbnail.s

To get Adobe Reader's thumbnails working on 64-bit machines, you can install this fix that I wrote: (You'll need to repair/reinstall Adobe Reader so that it is registered as the thumbnail handler for the .PDF filetype, if something else is currently registered in its place.)

Hi - I've got to do something as they are definitely not shutting down - if I look at my process list now for example I have 35 of them running!
I did try that fix with adobe and despite it saying that the fix had been applied it wasn't working - but now that I know I can get some help with it here I'll give it another try. The current setup is also problematic as locks seem to be held on files - perhaps because the processes are still running, but i thought having the preview as temp file would solve this - maybe it's more an issue with the thumbnails. I'll experiment further.

You may need to repair/reinstall Adobe Reader to make it the default PDF handler/viewer/thumbnailer again, before running the 64-bit fix, if PDF-Xchange is currently the default.

Ok, I've done a fresh install of Adobe 10.3 and your excellent patch/bridge and everything is now working in both DO and explorer and I'm no longer getting all the prevhost.exe tasks like I was with PDF-Xchange. I have to say, the thumbs look better in Explorer - I like the drop shadow, but DO improved a bit when I found I could untick the extra border. Only issue now - my icon overlay isn't working - it's getting hidden by the hide if type not registered option, even though it shows in explorer and the type is definitely registered. Perhaps it needs a reboot. Anyway I don't care about that - I'm happy now thanks for all your help and great thumbnail bridge Leo.

I too am running PDF-Xchange. I have just checked my Task Manager, and find seven instances of prevhost.exe.


I cannot remember the details now, but I switched to PDF-Xchange after having problems first with Abobe Reader, then with Foxit.

Looks like I am going to have to find yet another PDF viewer. I am not worried about the thumbnails.

I am running PDF-Xchange on W7 X64 and Opus and I don't have the same problem.

In my case, prevhost.exe disappears within seconds of closing the Opus viewer or navigating to another document (non PDF).

Regards, AB

Thanks guys - perhaps Leo can short-list which settings we'd need to compare to see what could be different between our setups. It's something to do with the way DO uses the viewer as the problem didn't occur with explorer. I'd prefer not to use Adobe if at all possible, just on principle...

BTW I was using PDF Xchange 2.5.203 on DO - you prob don't want to try if yours is working, but it would be interesting to rule out something that's changed in the pdfxchange versions - it's a reasonable change between 201 and 203 according to the excellent changelog:

There aren't really any relevant settings, unless you've manually edited the ActiveX plugin's XML config file. (There are a couple of very esoteric settings only accessible via the config file, but I doubt anyone has changed them.)

The difference must be in the version of PDF-XChange you both have, or something else on the system that might be getting involved (e.g. antivirus or tools which change how windows behave, or other things that inject code into other processes) or a system-wide setting (e.g. UAC being turned off on one machine and on on the other).

I just updated to 2.5.204 (17th July) and still don't see the problem you and Bernard report. I doubt if it makes any difference, but I am running the portable version of PDFX.

Regards, AB

I just updated to 2.5.204 (17th July) and still don't see the problem you and Bernard report. I doubt if it makes any difference, but I am running the portable version of PDFX.

Regards, AB[/quote]I was running PDF_X 2.5.204, standard version, and viewing my PDFs by double-clicking the file name in DO. This opens a new window to display the PDF.

I have now switched to STDU, deleted all the instances of prevhost.exe, and so far so good - no strange behaviour.

STDU is a multi-format viewer, which in addition to PDF, supports TIFF, DjVu, XPS, JBIG2, WWF, FB2, TXT, Comic Book Archive (CBR or CBZ), TCR, PalmDoc(PDB), MOBI, AZW, EPub, DCX and image (BMP, PCX, JPEG, GIF, PNG, WMF, EMF, PSD) files. At this stage, I am just using it for PDFs.

For the record, I am running DO