Resize Thumbnails in Windows Explorer

Create a DWORD key named ThumbnailSize under MyComputer\\HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer

Give it any value such as 128, 256, etc.

Article : If any of you out there like to use the thumbnail view, especially for browsing through photos and images, it can become a bit of a drain on your system. It is possible to lower the thumbnail size and quality by editing the following registry keys.

Open the registry and navigate to :

HKEY_CURRENT_USER\ Software\ Microsoft \ Windows\ CurrentVersion\ Explorer

Create a new DWORD value called ThumbnailSize, and set the value between 32 and 256.

And/or create another DWORD value called ThumbnailQuality, and set the value between 50 and 100.
Key Details :

USER Key:
[HKEY_CURRENT_USER\ Software\ Microsoft \ Windows\ CurrentVersion\ Explorer]
Value Name: ThumbnailSize
Data Type: REG_DWORD (DWORD Value)
Data Value: 32 - 256

USER Key:
[HKEY_CURRENT_USER\ Software\ Microsoft \ Windows\ CurrentVersion\ Explorer]
Value Name: ThumbnailQuality
Data Type: REG_DWORD (DWORD Value)
Data Value: 50 - 100