On Windows 7 Professional, support for Classic ASP on IIS 7.5 is not installed by default.
You have to install and enable it.
- Go to Control Panel
- Go to Program and Features
- Go to Turn Windows features on or off
- Expand Internet Information Services, then World Wide Web Services, then Application Development features.
- Select ASP.
- Click OK.
- Restart IIS or reboot your PC (better).