How did you install the Adaptec drivers? The package you get off the Adaptec page only lets you install if you've got Adaptec hardware.

If you Google for aspi_me you will find an exe that installs the Adaptec ASPI drivers even if you don't have an Adaptec card. You have to set the clock back on your PC to 1998 to install it though, the exe was time limited. Once you have done that you can upgrade the drivers to the latest version with the versions from the Adaptec website.