99% chance your media is bad. Try downloading again and/or checking the hash, try burning again or slower or using different software or drive, or try USB.
server 2008 32 bit installs fine but can't install server 2008 R2 64bit. When I try to I get a message stating that a cd/DVD driver is missing. I'm new to dell servers and can't seem to figure this out. Please help. Thanks. 
Poweredge 1950 can't install Windows Server 2008 R2 64bit