Failover cluster 2012R2 deleted VM cannot have the folder deleted

Hey guys.

I have a bit of a problem.

I have a Failover cluster 2012R2 and a bunch of VMs. The problem is that one of them (from a 40 batch I've created about a week ago) - that is VM22 - cannot have the folder deleted because of the VM's xml file which seems to be in use. I've remove the VM from failover cluster, from the hyper-v and when I moved on to delete its folder from cluster shared storage, i got the messages saying that the xml file is in use.

I didn't use this VM as a parent for another one, I'm not using its files in another VM (or at least not intentionally).

What would be the best scenario to check who or what is keeping the files open?

Thank you,

Gabriel