Yes, a new thread would have been better...
The installation DVDs contain both x86 and x64 versions. If you downloaded an iso from MSDN, then depending on version, you may have had the choice of one or the other, if there wasn't a choice, then the iso would contain both.
The installation DVDs do check the OS, if you prefer to install the other option (x86 on an x64), it's in the last tab on the first installation screen
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability