When we browse images in the explorer, the thumbnail size of the picture's is too small or too big and the quality of the thumbnail is not good, it is possible to make our own thumbnail size and make the thumbnails display in high quaility.
To do this it is required to edit the registry, so it is better to make the registry backup.
1. open the registry editor - start->run-> regedit
2. navigate to HKEY_CURRENT_USER\ Software\ Microsoft \ Windows\ CurrentVersion\Explorer
3. create two new DWord Value by right clicking and select "new->DWORD value" and name one as "ThumbnailSize" and other as "ThumbnailQuality"
4. select Decimal Value and set values for both, ThumbnailSize can have values 32 - 256 and Thumbnail Quaility can have values 50 - 100.
5. open any folder and change the view to Thumbnail and see the difference.