installation errors help needed please

I’m new to MODX, and have downloaded and attempted the installation, which appears to complete okay, but when I try to go to the manager, I get the following errors:

Warning: fopen(c:/Inetpub/wwwroot/modxb/manager/media/style//login.html) [function.fopen]: failed to open stream: No such file or directory in c:\Inetpub\wwwroot\modxb\manager\includes\accesscontrol.inc.php on line 83

Warning: filesize() [function.filesize]: stat failed for c:/Inetpub/wwwroot/modxb/manager/media/style//login.html in c:\Inetpub\wwwroot\modxb\manager\includes\accesscontrol.inc.php on line 84

Warning: fread(): supplied argument is not a valid stream resource in c:\Inetpub\wwwroot\modxb\manager\includes\accesscontrol.inc.php on line 84

Warning: fclose(): supplied argument is not a valid stream resource in c:\Inetpub\wwwroot\modxb\manager\includes\accesscontrol.inc.php on line 85

I am installing on a Windows machine using IIS, I’ve tried running the permissions wizard in IIS, but no change.

Any ideas would be very welcome...

it seems that all files did not get uploaded correctly. Try to upload the files again.