That’s even a better suggestion, because it’s a great opportunity to tune your computer with a SSD or at least a SSHD and unlike software promising to “speed up your computer” you really get a speed boost if you use something faster to boot from.

You can do a full reinstall of the OS in 2 hours and fully patched with software reloaded in another 45 minutes.
If you install from USB, especially from 3.0 (though with Windows 7 you need to make some [url=http://forums.anandtech.com/showthread.php?t=2280676]adjustments[/url]) with an USB 3.0 flash media, you could get the installation of Windows done in less than 10 minutes on a SSD, but even with USB 2.0 speed it's still faster than from DVD.
Partition the new drive to at least 3 partitions, separate your data from the OS[...]
It's easier to let Windows decide how to make the partitions and if you're making a backup of the whole drive - MBR/GPT initialization and boot information included, though to separate data, you could also either use an external drive or remove the optical drive and replace it with an SSD and separate Windows+programs on the one side and data on the other side.
Ran an internet Cafe with 15,000 through the front door in 5 months and never has a single infection of virus, spyware, maleware, etc.
Kiosk software is a great invention. ;)