Which version of 7 are you running? I'm aware of issues with the vmtools and 2022. I'd look at the VMs themselves - if you're using paravirtual driver that could be of issue - and it's not easy to fix. Update to the latest 7 vsphere, then your esxi hosts, then update the tools on the affected hosts in safe mode.

Another thing to check - if you can boot them into safe mode, its a virtual layer driver causing the hub bub.

This wouldn't be a hardware level thing cause you'd get exceptions or callbacks from vmware before the OS gets a chance to load and BSOD. Hope this helps.

Btw: where did you get your rack? I'd love that setup!