I just bought an 24" iMac and used bootcamp to partition the hard drive and installed Windows Vista Business on it. The OS is running fine however I can't get the Vista Aero theme to work. The iMac is running on ATI Radeon HD 2600 PRO w/256MB GDDR3 graphics card. This GC should have Shader Model 4.0 support and Aero only needs Shader Model 2.0 support. I went to personalized>Windows Color and Appearance and the Aero theme is not there as a selection and I also refreshed the index scoring, but it gave it a 1.0 rating. How should I fixed this so I can use Aero theme? Thanks in advanced.