How to format MS-DOS (FAT) to Mac OS??

Select the disk in Disk Utility, click the Partition tab, select 1 Partition from the Volume Scheme pop-up menu, click the Options button, choose GUID Partition Table and click OK. Choose Mac OS Extended (Journaled) from the Format pop-up menu and click the Apply button. In the sheet that appears click the Partition button and your flash drive will be formatted as a Mac OS X Extended (Journaled) drive.

Fine. Choose the entire disk, disk1s2, or if there there are two icons, the upper one. In Disk Utility, Erase tab, choose OS X Extended (Journaled) and name the volume. Press erase.

Hi dwb, I may have missed this step...

"select 1 Partition from the Volume Scheme pop-up menu, click the Options button, choose GUID Partition Table and click OK."

I thought that now, erasing the disk and reformatting automatically layed a GUID on it?

After selecting GUID partition table you still have to select which find of format you want. Is that what you are asking? (Which in this case I should have edited from my template to MS-DOS)

I read your question and saw what I expected, not what you actually asked. Sorry. Are you saying you have a drive that is formatted Mac OS extended and you want to reformat it for MS-DOS (FAT 32)? If so you can just select the volume, select the format you want, and apply. (A mounted drive has at least 2 icons in Disk Utility, the top one is the drive and the second is the volume. The drive is what you apply a partition to, the volume is what you format. A drive might have 2 volumes, one formatted FAT32 and one MacJournaled).

As far as I know there are no utilities that can format a volume without deleting files already on that volume.

My head is spinning 😮 Am I correct in assuming you mean you have one internal drive that now has 3 partitions - Sorta like this and that you are in Windows trying to copy files from Windows to the 3rd partition? If so, the reason it isn't working is because Windows cannot write to Mac formatted volumes without 3rd party software.Well, that was true prior to Lion, I've not begun playing with BootCamp under Lion. If that isn't the problem, try explaining again.

You say: Copying doesn't have anything to do with Boot Camp. But then you say: It's that i don't have permission to copy to the disk and that leaves me confused. What are your trying to accomplish and what program (or operating system) are you trying to use when you do it?

Ok - so while I was wrong about you having 3 partitions I was right that you were trying to copy from Windows to a Mac formatted volume. That isn't possible without third party software (MacDrive should you need it in the future) at least pre-Lion. As I said, I don't have BootCamp running in Lion in fact, since early days Snow Leopard - virtualization meets my needs.