I purchased 3 Dell Optiplex (small form factor) 755 from a local city hall. The 80GB HDDs have all been wiped. They gave me reinstallation disks with each unit that also has the COA label. When I try to reinstall the OS (Vista Business) I get through the basic install windows and then it acts as though its going to install, but an error message stating that the BOOTMGR cannot be found comes up. I've researched this a little on the Internet, but haven't really found a good answer as of yet. Will I need to install a full (new) version of Vista?