the name of my skin 'Blank'.  
when I install the skin.  I get an error about an inappropriate file in the skin.  I do not see this file in the skin, even when I show all files in windows explorer. 

i no longer even have a *.jpg file in the skin so there must be a cache issue or something.  I have turned of thumbnail caching on my local machine. 

but I still keep getting this error. 

Error processing file: Blank/Thumbs.db is a restricted file type. Valid file types include ( *.swf, *.jpg, *.jpeg, *.jpe, *.gif, *.bmp, *.png, *.doc, *.xls, *.ppt, *.pdf, *.txt, *.xml, *.xsl, *.css, *.zip). Please contact your hosting provider if you need to upload a file type which is not supported.
End processing zip file: Blank.zip

I just resolved this by recreating a new skin called blank2 which never had an image in the skin. 

if you copy images into your skin zip file it will also copy across the Windows thumbnail file for the images.

To view thumbnail files on your computer:

Open a folder
Go to the tools menu
select the view tab

- on the hidden files and folders
select the 'show hidden files and folders' radio button

You will now be able to view the thumbnails files. If you open your original skin.zip file you should see the thumbnail file inside the zip file and you can just select the file and press delete inside the zip file, you should now be to install the skin zip without errors.

Thanks,

Thanks Lee for your clear explaination.  There must be something wrong with my hidden files folder settings. 

I do not always see my hidden files, even though I know it has the right setting for the folder.   Other folders like windows does show me hidden files, so I just move on.   that was the very first thing I checked because of course I have run into those files when copying and pasting. 

Its great to have a guide in the Jungle!  Thanks

I need to go ask another question about the Cache Setting. 

I think if you view the content of your skin zip even with hidden folders view turned off it should display the thumbs file in the zip file, thanks