GUID Partition Table - is HDD reformat necessary ?

[cgizmo]

Hello,

 

I'm thinking of giving Mac OSX on a PC a go, but last time I tried this, it completely failed. Now that I have new hardware, i'm hoping to get it right - so here it is : I have a SATA drive, partitionned like so :

   Device   Boot    Start         End      Blocks          Id   System
/dev/sdb1   *           1        13373    107418591    7    HPFS/NTFS
/dev/sdb2           18278       21316    24410767+   83  Linux
/dev/sdb3           21317       30515    73890967+   5    Extended
/dev/sdb4           13374       18277    39391380     7    HPFS/NTFS
/dev/sdb5           21317       29583    66404646     83  Linux
/dev/sdb6           29584       30515     7486258+    82  Linux swap / Solaris

 

Basically, the idea would be to remove the 30 GB NTFS partition called sdb4, and install Snow Leopard onto it. The problem is, i've heard that one cannot install Leopard on an extended partition. Is there absolutely no way to do this ? And if there is a way, is 30 GB enough ?

 

Now if it is absolutely necessary to be on a primary partition, I could remove sdb1, and install Mac onto it - but i'm guessing this poses another problem : the partition table is currently in a "DOS layout". Mac OSX requires a "GUID layout" (right ?), so is there any way to convert the partition table to GUID, without having to completely reformat ?

 

Thank you,

cgizmo.