Cloning of server storage drives is unsupported and known to cause problems. The only supported way of recovering from these problems is server reinstallation.
You can try the following, but I don't guarantee it will work:
- Remove the 500 GB drive and replace it with the 160 GB drive (which I will presume is still effectively the clone source).
- Restart your server.
- Is everything okay? If so, then connect the 500 GB drive to your server using an external (usb, firewire, eSATA) enclosure or a SATA/IDE-to-USB bridge device.
- Add the 500 GB drive to server storage.
- Remove the 160 GB drive from server storage.
- Shut down your server and install the 500 GB drive internally.
- Restart your server.
If the above doesn't work, server reinstallation is your next option.
I'm not on the WHS team, I just post a lot. :)