If for some reason you have Photoshop .psd files and you dont have Photoshop installed here is a method so you can browser those thumbnails.
Is also a good method for viewing thumbnails of those files in Window explorer instead of the Photoshop icon in some versions of Photoshop.
The same is for Illustrator files all is include in the download.
1.Copy both .dll files to C:\Program Files\Common Files\Adobe\Shell if this folder doesn’t exist create it.
2. Run both .reg files one is for Illustrator files the other for Photoshop files.
3. Reboot if needed.
Get it here
*If you found the info useful or if have any problem with it please comment