Windows 2008 SBS updates hanging 3 of 3 0% complete

Microsoft Windows 2008 Small Business Server Updates Installing Windows 2008 SBS on Dell 2900. Builds succesfully, If I try to install any windows updates as soon as a reboot is required it hangs at stage 3 of 3 0% complete. Left it running overnight and it completed but tried to install other updates and hung again 3 of 3 0% complete … gave up on it after 2 hours waiting. Any suggestions?