In your BIOS what are your SATA settings? (AHCI, Compatibility, IDE, RAID, etc?) If your SATA HD is set to AHCI you may need to load the appropriate drivers prior to the initial. Also, you might want to consider a custom or "clean" install as Sturm suggested as you may receive better performance as well as an enhanced experience.
Should you require additional assistance and as well as further guidance, Microsoft does have an official Windows 7 Support Forum located here http://social.technet.microsoft.com/Forums/en-US/category/w7itpro/
. It is supported by product specialists as well as engineers and support teams.
Microsoft Windows Client Team