"SBS 2003 contains a version of Exchange and Sharepoint that are specifically NOT supported under Hyper-v. Since these are integrated into SBS 2003 it too becomes unsupported on Hyper-v. This doesn’t mean that it won’t run it simply means if you call MS for support of any issue with SBS 2003 and are running on Hyper-v you won’t be able to get any support."
"Why would you want to do this? Why not go straight to SBS 2008 on Hyper-V if you’re doing a hardware refresh?
I think this can be a stepping stone for a customer going from SBS 2003 to SBS 2008 but who needs new hardware. You can sell them a new server, virtualise SBS 2003, they have new hardware with no impact on their current setup/configuration. They are happy with you and maybe more likely to buy SBS 2008 at a later date especially in the current economic climate. Obviously they have to have the appropriate license to be able to virtualise SBS 2003."