Web Platform Installer
Cannot Install PHP 5.3.13 for WebMatrix
Last post May 25, 2012 05:24 AM by mamba dai - msft
May 22, 2012 04:48 PM|cbartell|LINK
May 25, 2012 05:24 AM|Mamba Dai - MSFT|LINK
The process cannot access the file 'C:\Program Files\iis express\PHP\v5.3\ext\php_curl.dll' because it is being used by another process
This error hints there is another process is using "php_curl.dll" file.
We currently have multiple Word Press sites set up in IIS. This is holding us up from installing a site for a client.
You said there are multiple Word Press sites set up on your IIS. The WordPress may be using the php dll file, so leads to access the the same php dll at the same time and the installation fails to finish.
In a nutshell, this error "the process can't access the file ...." indicates this file(php_curl.dll) is inaccessible. Please check whether this file is used by another application/process.