Vista keeps deactivating with events hardware has changed

I just reformatted my system and reinstalled vista. It's been about a month and vista keeps deactivating itself. I looked in the event log and found the following:

Event ID: 8200 : Security-Licensing-SLC
License acquisition failure details.
hr=0xC004C008

Event ID: 1014: Security-Licensing-SLC
Acquisition of End User License failed. hr=0xC004C008
Sku Id=33a7e8d3-e2ab-413b-96a6-27c83b21c695

Event ID: 8196
License Activation Scheduler (SLUINotify.dll) was not able to automatically activate.  Error code:
0xC004C008

Event ID: 1024
The hardware has changed.  <-----This happens constantly in the logs

All in that order, but 1024 repeats about every 10-15 minutes, which in turn causes vista to deactivate and I have to call MS again.

I have the same hardware and only use a hard drive dock to work on clients systems backing up data. This runs from usb and shouldn't cause that.

Any ideas?