Use the SysAngel DVD Generator :
Provide your original Microsoft Windows CDRom and serial number
Let the DVD Generator download Service Pack, hotfixes, drivers, software, and integrate every needed stuff on a unique, bootable, DVD
Then, boot the DVD on the computer on which you need to install or reinstall Windows, answer a few questions (5 minutes), and leave the computer.
Come back 2 hours later: everything should be up and running.