I\'m assuming this is possible in the applicationhost.config file but I did not see a parent paths setting.
How do you allow parent paths for a specific site running und
The following should get you going.
On 32bit system "%programfiles%\iis express\appcmd" set config "Default Web Site/myapp -section:asp -enableParentPaths:true
On 64 bit system"%programfiles(x86)%\iis express\appcmd" set config "Default Web Site/myapp -section:asp -enableParentPaths:true
Link to related IIS 7 config reference: http://www.iis.net/ConfigReference/system.webServer/asp