I've never run mandriva but i would assume i you just do an update it will find a new kernel as well as several other updates
To upgrade automatically use MandrivaUpdate or urpmi. The verification
of md5 checksums and GPG signatures is performed automatically for you.
All packages are signed by Mandriva for security. You can obtain the
GPG public key of the Mandriva Security Team by executing:
gpg --recv-keys --keyserver pgp.mit.edu 0x22458A98
you might look over on the distro-> mandriva forum about how to do the updates.
found this there
http://www.linuxquestions.org/questi...d.php?t=470217