I'm trying to upgrade C5 via the dashboard

The latest version of concrete5 is 5.4.2.1. You are running 5.4.1.1. Update Now!

However when I try to update I get a run of errors such as below. Is the error from the chmod function a permissions error as this is our work server?


Warning: copy(d:\inetpub\wwwroot/updates/concrete5.4.2.1/concrete/blocks/autonav/add.php) [function.copy]: failed to open stream: No such file or directory in D:\inetpub\wwwroot\concrete\helpers\file.php on line 79

Warning: chmod() [function.chmod]: No such file or directory in D:\inetpub\wwwroot\concrete\helpers\file.php on line 80