Do you have VMware Fusion? Have you ever witnessed one of your virtual machines in Fusion failing to boot or fail with a STOP 7B blue screen error?
If your answer is yes, then this video might be of some help to you.
This video is based on VMware Knowledge Base article A virtual machine in Fusion fails to boot or fails with a STOP 7B blue screen error (2013268).
If the problematic virtual machine in question was imported from a Boot Camp partition, was created with Migration Assistant or imported using vCenter Converter, then it might be failing due to incorrect SCSI drivers. It is possible that there might be some software installed within the virtual machine that specifically requires an IDE disk.
In these instances, you might need to change the virtual disk type. This video discusses and demonstrates how to change a virtual disk from SCSI to IDE in VMware Fusion.