Hello, I would like to use my ubuntu computer (2.2GHz Dual core Sempron, 2GB DDR2 RAM and a 500GB HDD) as a personal server, almost like a networked external HDD. I assume this means I need a file system that will work with both windows and Linux, ie: NTFS windows only ext2 & 3 linux only. I have been told that FAT32 is only going to work is my HDD is under 160GB. Can you confirm or deny this? Also I use a separate 80GB PATA HDD for the ubuntu installation, the 500GB is the one I need to be accessible under both windows and linux. If anyone can help that's great, also if you can think of any potential problems I may come across yell out.

Thanks!

Decided to go with FAT32, still want you opinions tho!! Also how do I set the HDDs permissions so that any computer plugged into it will have unrestricted access to the drive but no access to the 80GB HDD.

Its not clear if you mean you want to dual boot Ms and Linux & have them share data, or use your Linux system as a server and connect from MS over your lan?

In the former case you can use NTFS or ext3; both OSes have the ability, via utils to read/write either.
In the latter case, the 2 most likely tools are Samba or NFS; your choice.