Installing Windows 7 using unsigned drivers

With Win 7, Microsoft removed some very important drivers that were present in the Vista installation driver kit, including drivers from well-known workstation SCSI controllers.
If you have 15k RPM SCSI drives that you still want to use with an older controller, you can’t with Windows 7.
Installing Windows 7 on older SCSI controllers will fail because the controllers will not be detected and setup cannot find your SCSI HDDs.