If you are running copies of a guest (or imported a physical PC), you MUST run NewSID and change the computer name as well, or run SysPrep.
What happened was our co-worker actually made the image. We were responsible for installing some software on it and one of the CD's we were installing crashed after that when we loaded up the VM it would give us the error.
Regarding your post earlier with NEWSID or SysPrep what is that?
Every Windows PC has a Security Identifier (SID) associated with it - and if the PC is on a domain, the SID must be unique. SysInternals' utility, NewSID, will generate a new SID for your computer - used when ghosting/imaging/etc. You will still have to manually change the computer name. Microsoft's SysPrep utility is an all-in-one utility for both tasks and additional customization of clones/images.
Newsid download page :
Sysprep is available in the deploy.cab file in the support folder of your windows cd.
Newsid is the quick and easy way of changing the sid. I personnaly use sysprep since it avoids someone forgetting to change the sid and cause issues... sysprep information is located in the deploy.cab file as well