No.
You need to treat a VM just like any other physical machine when it comes to that sort of thing. There are many internet tutorials that cover accessing windows without knowing the password, and the method is often dependent on whether it was a local or microsoft account. If you used MS account credentials you should be able to reset them on the MS site, as long as you have access to the linked email account.
If you just want to see what is on their virtual hard drives, you can add them to another VM as a second disk, then mount them in the disk manager as long as the drive wasn't encrypted, same as you would physically plug a hard drive in to a known good machine to check its content.
You can also change the boot order for the VM so it boots off the Windows install media, which is part of one method to reset windows passwords.
Bottom line, Unraid can't do anything special when it comes to windows security, if you find a method for a physical machine and need help translating the specifics to a VM, feel free to post and ask.