I have completed numerous WordPress installs on Unix without a problem but never IIS.
I have a client using WebCentral for hosting and IIS is all they offer.
I had to have PHP and MYSQL added to the account, I downloaded the latest WP install files and all was running smoothly until WP tried to create the wp-config.php file (had to do it manually), and I tried to set up a custom structure for permalinks (and got the "If your .htaccess file were writable, we could d..." message) and I tried to automatically update a plugin (I got this message "Unable to locate WordPress Content directory (wp-content).") and I tried to add a new plug in (same as previous message).
For me, all problems pointed at permissions errors however I had WebCentral check and when they looked exactly as suggested in the documentation, I was told to ask on the WordPress forum.
Does anyone have any suggestions? I want to exhaust all avenues before telling the client he needs to change hosting company.
I have added a phpinfo call in the footer if it helps: