I want to upgrade my Cisco Callmanager version from 4.1 to 6.1.My server is HP Compaq Proliant GL320 G2.I upgraded my server 2*80GB HDD and 2GB RAM.Buy I have error Grub Loading Stage 1.5 Grub Loading please wait.... Error 21 when I installed 6.1 DVD. Can you help me for this problem. Thanks,