Hi , I'm running a 15-inch, Late 2011 MacBook Pro, and currently have Windows 7 x64 and Mac OS X 10.7.4 dual-booted across the 750GB hard drive. I want to install Ubuntu to make a triple-boot setup, but when looking at the drive map I noticed that I have 4 partitions, and because the disk is has a MBR partition table, I can't make any more. Here is the report from running rEFIt's "Partition Inspector" on my laptop: Code: *** Report for internal hard disk *** Current GPT partition table: No GPT partition table present! Current MBR partition table: # A Start LBA End LBA Type 1 40 409639 ef EFI System (FAT) 2 409640 629557247 af Mac OS X HFS+ 3 629557248 630827007 ab Mac OS X Boot 4 * 630827008 1410699263 07 NTFS/HPFS MBR contents: Boot Code: Unknown, but bootable Partition at LBA 40: Boot Code: None (Non-system disk message) File System: FAT32 Listed in MBR as partition 1, type ef EFI System (FAT) Partition at LBA 409640: Boot Code: None File System: HFS Extended (HFS+) Listed in MBR as partition 2, type af Mac OS X HFS+ Partition at LBA 629557248: Boot Code: None File System: HFS Extended (HFS+) Listed in MBR as partition 3, type ab Mac OS X Boot Partition at LBA 630827008: Boot Code: Windows BOOTMGR (Vista) File System: NTFS Listed in MBR as partition 4, type 07 NTFS/HPFS, active (note that there is 25gb of free space after the last partition, which doesn't show up in this report) As far as I can see, I have these options: Convert the MBR to a GPT This website seems to show that using 'gdisk', I'd be able to write in a GPT over the top of the existing MBR, however this is risky, and in addition, could cause problems with booting Windows and Ubuntu (This article says "Booting is only supported for 64-bit [Windows] editions on UEFI-based systems." - is a macbook a UEFI system?. Also I'm not sure how Ubuntu would handle it) Delete the EFI boot partition to free up a MBR partition From reading some stuff online about this partition, it seems I could safely delete it, but this might screw over later firmware updates. Backup and delete the "Mac OS X boot" partition (Recovery Disk) to free up a partition Again, I could safely do this, but the recovery partition is there for a reason I guess... What would be the best way to proceed? Has anyone else had any experience with a situation like this?