Hi BigZed, and welcomr to the vista forums
The errors you outline would suggest that the original vista partition/drive is not present,
when you installed your new card did you make any changes to the Bios?
Obviously you had to open the case to install your new card so you may want to check the physical connections inside the case as they may have been loosened during the install and then disconnected after re-assembly.
you would only have to load drivers if the system is set up for RAID drives and needs drivers loaded before Vista loads. If this was not the case before the upgrade then changing the Video card would not change this
Personally I would check the cables.
also when you upgraded the card did you remove the existing drivers before you started the removal of the existing card? If not then it may be wise to start into safe mode un install the drivers , restart in normal mode let vista load the default drivers for the new card which you can then upgrade to the latest from the manufacturers site