I have the same error also.
Navigate to wordpress root/wp-content/plugins/
and rename codesnippet-20/
to codesnippet
Two things to consider:
1) there is an extra directory when extracting the plugin on the desktop. Only the deepest directory (named codesnippet) and its contents should be uploaded.
Should be: /plugins/codesnippet – not –
/plugins/codesnippet-20/codesnippet – or- /plugins/codesnippet/codesnippet
2) Beware of compatibility issues that might be present,
Requires WordPress Version: 2.0 or higher
Compatible up to: 2.8.1
Last Updated: 2009-8-3
…and perhaps report your results in the “says it works, says it’s broken” section of the download page.