Have you tried exploring the DVD contents and clicking on setup.exe? Hold down the shift key whilst you insert DVD in drive (this stops Autorun DVD) so you can explore the contents.
answers.microsoft.com/office2007-officeinstall/microsoft-office-2007-enterprise-setupexe-wont suggests solution. Also note: Office 2007 is 32-bit only but will run in a 64-bit Windows OS. Office 2010 is the first that has both 32 and 64 bit version though the 32-bit still works in a 64-bit os.