It depends a lot on the configuration of the VM and the capabilities of the host on which it was running, so it's not possible to give any sort of guaranteed answer. We put a lot of effort into maintaining compatibility with older VMs (powered off, snapshotted and/or suspended), but the big gap between WS 4 and WS 12 might make things difficult.
If the VM was earlier suspended on a system with WS 4.x and you migrate it to WS 12.x running on the same host system (with no hardware changes), that would give the best possible chance of success. If you're migrating it to a new host with a newer CPU, that will frequently (but not always) be successful -- it will fail if the CPU is lacking some feature that was used by your suspended VM If you are changing between an AMD processor and an Intel processor, it's very unlikely to succeed. There are many other factors which could also affect the outcome.
I encourage you to back up the VM first and then give it a try... Please report back with the results!
If you can't resume the VM on WS 12, you should be able to use WS 12 to forcibly power off the VM and clear out the suspended state. That should allow you to power on the VM again and boot it up afresh. The effect upon the VM is the same as if a physical PC had lost power at the moment it was suspended, so the OS might be a little bit angry about not being properly shut down and inconsistent filesystem state and so on.
Good luck!
--
Darius
