I have a 300GB haddrive and it is formatted for Mac OS Extended (Journaled). I also want to be able to use it on my PC. Is their a way to partition say 30GB to work on windows?
Interestingly, Disk Utility doesn't seem to allow one to do that with partitions. In order to use it to format a drive as FAT32, one has to select the actual 'root' drive for the option to show up. If one selects the 'named' drive or a partition, your options are HFS+ish, UFS, and "free space" (whatever that is). Maybe you should just create the partition map with the Mac and see if you can FAT32 format the partition with a Windows box?
If your drive already has data on it, and you're attempting to use Disk Utility to repartition it, yes, everything will get erased. If it's blank and you partition it now, and want to format one partition later FAT32 on a Windows box, AFAIK, only the partition that you want to format will be erased.. same as it would on a Mac. Is there a 3rd option that you're referring to that I'm missing? It's Friday and I cannot concentrate very well..