Thumbnail preview in explorer not showing thumbnails, instead default program icon

Hi Sunny,

Windows keeps a copy of all of your picture, video, and document thumbnails so they can be displayed quickly when you open a folder. The thumbnail preview problems can be resolved by clearing the thumbnail database and let the system rebuild it as and when required. To do so, use these steps:

Steps to Clear the Thumbnail Cache using Disk Cleanup

a.    Click Start, type “cleanmgr” (or typedisk cleanup) without quotes and press {ENTER}

b.    Select the system drive letter from the drop-down.

c.    Uncheck all the entries, except Thumbnails

d.    Click OK, and click Delete Files to confirm.

Alternatively, you can build thumbnail cache by going to the location below

%LocalAppData%\Microsoft\Windows\Explorer

The thumbnail database is stored globally in Windows 7 & Windows Vista, unlike Windows XP, where the thumbnail database is stored on a per-folder basis. In Windows 7 & Windows Vista, the default thumbnail cache location is as mentioned above.

Hope this information is helpful and let me know if you need any further assistance.

Mouneshwar R – Microsoft Support

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I found the solution in my case accidentally.  My kids started to play Minecraft on this laptop and I realized immediately that they would do well to have more RAM.  Lo and behold, after upgrading from the stock 2 GB to the max 8 GB, all the thumbnails suddenly appeared successfully and there has been no further problem!  Yay.  It seems to me Windows 7 uses a lot of RAM to the point that 2 GB is not enough for it to perform as advertised.  HTH someone.