If you are having a task installing using the upload feature it is probably that WP needs this first!!
What I did was:
Downloaded the file ftp-upgrade-fix.1.0.zip to my 'puter.
Extracted the file - 2 php files in one folder.
Used filezilla to upload the folder to wpcontent/plugins/
Went to the WordPress admin, opened plugins and activated the new plugin.
Works a treat!