I installed the Snow Leopard v 10.6.2, on a partition of size 160GB. But, later i required a separate partiton, so i used the Disk Utility option to create the partiton, which successfully created the partition of 80gb each. Now when i reboot the system it shows me following error "NO Bootable device -- Enter Boot disk, press any key". and it just stucks there. So i went through few forums and found the solution that i require the MAC OS X Bootable disk to boot from desired partition, which i did and it worked. But, now everytime i have to put the OS X DVD to boot MAC, which really annoying. Also, when i type diskutil list, i get the following output. # TypeName Size Identifier 0 GUID Partition 160GB disk0 1 EFI 209MB disk0s1 2 OS X 80GB disk0s2 3 BackUp 79.40GB disk0s3 I dont know where am i missing, i guess partitioning the HDD has modified my GUID Table, if YES then how to recover it back, or is their anything else am i supposed to do.