Changing Thumbnail Options
You can change the size of the Thumbnails view in My Computer by opening up the Registry Editor (regedit.exe) and navigating to the following location:
Current user only:
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Explorer
HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Explorer
Add a new DWORD value called ThumbnailSize and give it a hexidecimal value that is between 32 and 256, inclusive (that is, the lowest possible value is 32 and the highest is 256): A value of 32 will give you the smallest possible thumbnails, and 256 will give you the biggest. Experiment a bit to find your sweet spot.