Install Win7 on GUID drive, after 3 partitions?

[JustinAiken]

I've seen lots of guides that say you can install Win7 on a GUID drive, but you need to have a NTFS partition in the first 3...

 

I have right now:

 

-HFS

-HFS

-HFS

-NTFS

-NTFS

 

All of the HFS's are occupied by Leopard installations that I can't ditch... the NTFS's are empty... I'd like to join them in fact... But is it possible to install Win7 on there?

[srs5694]

Windows, even version 7RC, will not install on a "pure" GPT drive on a BIOS-based computer. I've tried. The installer just plain refuses to touch the drive. It will reportedly install on such a drive if the computer uses EFI rather than GPT, although I've not seen this with my own eyes.

 

What you can do is set up a hybrid MBR to give MBR-style access to one or more of your partitions. In fact, I've just written a rather lengthy Web page on hybrid MBRs, in conjunction with a utility I wrote that can do the job (GPT fdisk, aka gdisk). If I understand your situation, GPT fdisk will do what you want. Some earlier utilities would just create a hybrid MBR from the first three GPT partitions, which is probably where you're getting your information about the need for NTFS in the first three partitions. GPT fdisk doesn't have this limitation, though; it can set up a hybrid MBR using arbitrary partitions.

 

That said, hybrid MBRs are ugly, ugly, troubleprone, dangerous things. You might find one to be necessary in your case, but I just want to give you a heads-up that your task could get frustrating. Read my page and you'll learn about some of the pitfalls.

[JustinAiken]

Rod, that does look complicated! I just gave up and put Windows 7 on my slow drive instead of cramming it on the veliciraptor.... maybe there's a way to clone it back onto the GUID drive?

 

Also, you seem to know a LOT about partitions, maybe you can help me with a much more pressing problem...

 

Using gparted, I accidentally clicked the mfext flag on my main Leoaprd partition, and then the drive name disappeared and the file system changed from HFS+ to microsoft reservered....

 

I really need to get that partition back, is that possible?

[srs5694]

Also, you seem to know a LOT about partitions, maybe you can help me with a much more pressing problem...

 

Using gparted, I accidentally clicked the mfext flag on my main Leoaprd partition, and then the drive name disappeared and the file system changed from HFS+ to microsoft reservered....

 

I really need to get that partition back, is that possible?

 

PM sent, but for the benefit of others who may read this in future: My GPT fdisk (aka gdisk) program (http://sourceforge.net/projects/gptfdisk/ or http://www.rodsbooks.com/gdisk/) will do the trick. Use the 't' command on the main menu to change a partition type code. Be sure to write the partition to disk using the 'w' command after you make changes.

 

If you don't have a working Linux or Mac OS system, you can download Parted Magic, which is a Linux emergency system that includes GPT fdisk.

[JustinAiken]

Voodoo!!

 

 

GPT fdisk (gdisk) version 0.3.1

 

Found valid GPT with protective MBR; using GPT.

 

Command (m for help): p

Disk /dev/sda: 586072368 sectors, 279.5 GiB

Disk identifier (GUID): 2538BC36-C8A4-4926-8430-3648D5EBB319

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 586072334

Total free space is 5076 sectors (2.5 MiB)

 

Number Start (block) End (block) Size Code Name

1 40 409639 200.0 MiB 0C01 EFI System Partition

2 409640 147210279 70.0 GiB EF00 Untitled (EF00 = EFI?)

3 147210280 305020967 75.2 GiB 0C01

4 305020968 462307367 75.0 GiB AF00 Untitled

5 462307368 586067264 59.0 GiB AF00

 

[srs5694]

Voodoo!!

 

No, just weird nomenclature on the part of Parted (and its relatives, such as GParted), along with a gdisk-specific partition type code system.

 

(I'm going to reformat the below for clarity....)

 

GPT fdisk (gdisk) version 0.3.1

Found valid GPT with protective MBR; using GPT.

Command (m for help): p
Disk /dev/sda: 586072368 sectors, 279.5 GiB
Disk identifier (GUID): 2538BC36-C8A4-4926-8430-3648D5EBB319
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 586072334
Total free space is 5076 sectors (2.5 MiB)

Number  Start (block)	 End (block)  Size		Code  Name
  1			  40		  409639   200.0 MiB   0C01  EFI System Partition
  2		  409640	   147210279   70.0 GiB	EF00  Untitled					   (EF00 = EFI?)
  3	   147210280	   305020967   75.2 GiB	0C01 
  4	   305020968	   462307367   75.0 GiB	AF00  Untitled
  5	   462307368	   586067264   59.0 GiB	AF00

 

You can view GPT fdisk type codes by typing 'l' at a command prompt. You can also obtain details, including type code names, by typing 'i' at a command prompt (the program will prompt for a partition number). FWIW, I used the 4-character hexadecimal type codes in gdisk because the real type code is a GUID number, which takes 36 characters to display or enter. I needed something much shorter, and there was no standard for this. I therefore devised a conversion scheme that uses codes related to MBR codes; for instance, MBR code 0xAF becomes gdisk code AF00.

 

The gdisk type codes you've got are:

 

• 0C01 -- This is the Microsoft Reserved partition, made infamous by Parted. Parted has incorrectly applied this code to partitions 1 and 3. Partition 1 should almost certainly be gdisk type EF00. Partition 3 is more of a mystery (see below).
  
• EF00 -- This is the code for an EFI System Partition. Parted applies this code when you mark a GPT partition as being bootable. Chances are you did this to partition 2 yourself, since it's (presumably) your Mac OS X boot partition. This sounds like the right thing to do for a boot partition, but it's not. That partition should be of type AF00 (in gdisk parlance), and it should not be marked "bootable" in Parted, since "bootable" in Parted-speak means "EFI System Partition."
  
• AF00 -- This is the gdisk type code for Apple HFS/HFS+ partitions. It's correctly set on partitions 4 and 5, and should probably be set on partition 2.
  

 

The real mystery is partition 3....

 

 

According to GParted, partition 3 is an empty or near-empty NTFS partition. If that assessment is correct, then it's possible you mistakenly reformatted it for NTFS. If that's true, any HFS+ data from that partition is now lost (unless you want to pay for very pricey data recovery). OTOH, it's possible that GParted's filesystem identification code has messed up and that it's really got HFS+ data on it. In that case, you should be able to change the partition type code to AF00 (in gdisk) and mount the partition in Mac OS.

 

Your first message said you had three HFS+ partitions followed by two NTFS partitions. Neither GPT fdisk nor GParted shows that. It's conceivable that you thought partition 3 was at the end of the disk, which could partially explain the discrepancy. (Sometimes partition order and disk order don't match, so what's now partition 3 might once have been partition #4 or #5, despite covering an earlier part of the disk. Some utilities automatically sort disk partitions so that their numbers match their disk order.)