1.KDE LANGUAGE LOCALE
You need to be running KDE as root user (not <your-username>super-user) to change its root user language locale.
At the KDE login screen, select Console login. (If connected to the internet, it is a good idea to disconnect the cable, for security, whilst running as root). Log in as root, then
# startx
If this is the first time, the KDE configuration wizard should start (otherwise it's available via the Menu for Control Center), and you can select your country and language.
Then log out of KDE.
Then log out of root; after a few moments the KDE login screen should re-appear.
Reconnect the internet cable if applicable, and login as normal user.

This should work for Qtparted as well as Konqueror, as they share some libraries (but see below).

2.QTPARTED
Knoppix 5 uses libparted1.6. It allows different levels of access different filesystems (vfat, ext2,ext3...).
You will get increased functionality by upgrading to libparted1.7.
If you want to keep qtparted as the front-end, upgrade qtparted to debian unstable (valid at date of posting 6 January 2006)
An alternative to qtparted is gparted (from debian testing or unstable to use libparted1.7, as at 6 January 2006).

3. Good luck !