...Imagine how slow it would be for Windows (file) Explorer to have to open one of my directories that is full of > 1 Gig PS files just to extract the tiny embedded thumbnail from each...
That's not quite how it works.
Windows creates its own thumbnail images and stores them in a database. If you have 'Show Hidden Files' enabled you will see a 'Thumbs.db' file created in a any folder containing at least one image file.
Once the thumb is created and stored in the database a reference to it is written in the Thumbs.db file.
Upon opening the folder the Thumbs.db is immediately read and the image thumbnails called from the database. This is almost instant.
Without the correct dll file to decode PSD files, Explorer could never even start to create a database of thumbnails....it just doesn't know what they are.
Upon installing the right codec via the 3rd party application suggested by gedstar, allowing Explorer to now create thumbnails does indeed mean that initially a folder full of large PSD images will take some time to process but as long as the Thumbs.db file remains intact and in the folder then this only has to be done once.....in fact it can be done over a period of time .... each time the folder is opened more files will be processed until they are all done. Additional files are processed the next time the folder is opened.
You could even open the folder and just let Windows process the files while you get on with something else, then close the folder when its finished, even the most basic of PC's should be able to do that without coming to grinding halt.
Opening the folder at a later date should then pull those thumbs from the database making it almost instant....as long as the Thumbs.db file is intact and in the folder.
The software suggested by gedstar certain does the job...for me anyway. One situation whereby thumbnails would never (and never have) worked was over a network...this is now fixed, as is large PSD file thumbs...sorted.
The only thing it fails on is PSD files on the desktop...they still show as an icon but how often do you store PSD files on the desktop? (The folder is fine though, its just 'on' the Desktop that fails.)
The good old trusty stable 'SageThumbs' was really good and is still worth having installed, but Pictus just adds that missing piece of the jigsaw.
Thanks again gedstar.
(See what I did there......THUMBS-up!)
Never mind...I'll get me coat.
Regards.
MrToM.