The image thumbnail size in Windows 7 is just small to understand images by looking at the thumbnail. You need to open each image one at a time to see what it is. Instead of opening one photo after another just change the thumbnail image size such that you can make out the images at a glance.
To change the thumbnail image size in Windows 7 you need to do some simple changes to its registry editor. It is recommended that you create a backup of Windows Registry, to know how to back up Registry click here.
1) Click on the start button and click on Run to open Run dialog box (0r) Press and hold Windows key and press R key to open Run dialog box.
2) Now type “regedit” in the place provided and click Ok.
3) You can now see Registry Editor window, in the left hand side you can see an entry named HKEY_CURRENT_USER click on the + sign next to it then Softwares –> Microsoft –> Windows –> Current version > Explorer.
4) Select Explorer, to the right hand side you should see an entry named ThumbnailSize double click on it.
If the entry is not present then Right click on Explorer –> New –> DWord Value and name it as TunmbnailSize and press enter.
5) Now double click on the ThumbnailSize entry and set the value you want between 32 and 256. The higher value you set, the larger will be the image thumbnail.
That’s it you have changed the image thumbnail size in Windows 7. Close Registry Editor and go to a folder that contains images to see larger image thumbnails.
This tweak applies even to other Windows Operating system versions like Vista and XP.