Downgrade your Lacie 5big office to WHS 2003

I got a nice Lacie office box as a replacement for my old server
My old server was using 120 Watt power, This one only use 40Watt.

This box is running Windows Homeserver 2011 and i was very disappointed about this OS
I was used to work with WHS 2003, and i love this version. Its simple, and it can be used to backup up almost any OS like XP, Windows 2003, Windows 2008 both 32 and 64 bits

For WHS 2011 backup, you need to install framework 4, and it will not even backup a 2003 file server.

So i was wondering if there is a (legal) way to install WHS 2003. I know there was a 5big release with the name “5big backup” and this one is running 2003
I did search on the Lacie site and found this

http://www.lacie.com/support/drivers/driver.htm?id=10209

I just wanted to play it safe, so i swap the drive for a black testdrive and try to setup the server with the downloaded 5big backupserver recovery
To my surprise it just worked, and now i have my server running with WHS 2003