I have developed a HTTP Handler Web Service, and have had it successfully deployed, through testing on other environments i've ran into another problem. This is the error message I receive:

You have attempted to execute a CGI, ISAPI, or other executable program from a directory that does not allow programs to be executed. 
HTTP Error 403.1 - Forbidden: Execute access is denied.
Internet Information Services (IIS)

So it is obvious what needs to be fixed, so:

1) Start Internet Information Services (IIS) Manager.
2) Right-click the Web site that contains the SharePoint Web site that you created, and then click Properties.
3) Click the Home Directory tab.
4) Under Application settings, click either Scripts only in the Execute permissions list or Scripts and Executables in the Execute permissions list (as appropriate to your situation). Click OK.
5) Quit IIS Manager.

But I'm still getting the same error. So what else could be wrong?