Creating a .reg file for Windows 7
I don't know how those quotes ended up in that file, but I would assume those don't work (maybe you copied it off a Wordpress blog).
Besides anything else, I think it should be like this:
[HKEY_CLASSES_ROOT\Folder\shell\PngCrush]
@="PNG Crush"
[HKEY_CLASSES-ROOT\Folder\shell\PngCrush\command]
@="E:\Programs\PNGCrush\crush.bat %1"
That's not the valid syntax of a registry file, it's missing the header.
Add a line in front with: Windows Registry Editor Version 5.00
Check whether there are invalid characters, if you saved the file in Unicode that could be the problem.