I have 3HDs, i was just using 2 of them, one with mandriva 2005 le, and the other one with win xp. Both master, so i switch cables everytime i want to swap versions. So I decded to use the other HD as a back up disk, so i can save files to that hd and use them both in linux and windows. I first formatted the disk in windows, using fdisk creating a primary DOS partition, linux recognized it but was unable to read or write. (it only shows in hardDrake) hdb. Then i formatted it in linux, and it doesn't show in windows.

Is there any way i can get it to work w/ both?

You should format the spare disk with fat32.
After formating the disk, you have to change the entires in /etc/fstab.

spare disk is third hdd. master at secondary ide: hdc(a), slave at same channel: hdd(b)

entry in /etc/fstab:

(a)
/windows /dev/hdc vfat auto,rw,defaults 0 0

(b)

/windows /dev/hdd vfat auto,rw,defaults 0 0

at last create a folder in the base directory named windows.

I tryed
/windows /dev/hdc vfat auto,rw,defaults 0 0
and
/windows /dev/hdd vfat auto,rw,defaults 0 0
and neither worked, so as hardrake says it's hdb, i changed it to hdb.

When i try to mount the drive it says it must be mounted by root, so i change to the root account and try to mount it , it dows nothing. If anybody can help me....

here's a copy of my fstab
/*
# This file is edited by fstab-sync - see 'man fstab-sync' for details
/dev/hda1 / ext3 defaults 1 1
/dev/hda6 /home ext3 defaults 1 2
/dev/hdc /mnt/cdrom iso9660 user,iocharset=iso8859-1,noauto,ro,exec 0 0
none /mnt/floppy supermount dev=/dev/fd0,fs=ext2:vfat,--,umask=0,iocharset=iso8859-1,sync,codepage=850 0 0
none /proc proc defaults 0 0
/dev/hda5 swap swap defaults 0 0
/dev/hdd /mnt/cdrom2 auto umask=0,user,iocharset=iso8859-1,sync,codepage=850,noauto,ro,exec,users 0 0
/dev/hdb /windows vfat auto,rw,defaults 0 0
/dev/sda1 /mnt/removable vfat pamconsole,exec,noauto,noatime,sync,codepage=850,iocharset=iso8859-1,managed 0 0
*/

This is what hardrake says about my spare disk,
/*
Identification
Vendor: ‎Samsung

Model: ‎SV0511D

Media class: ‎hd

Bus identification
Device ID: ‎1

Connection
Bus: ‎ide

Channel: ‎primary

Device
Old device file: ‎/dev/hdb

New devfs device: ‎/dev/ide/host0/bus0/target1/lun0/disc

Partitions
Primary partitions: ‎1 (hdb1)

Misc
Geometry: ‎659/240/63 (CHS)

Disk controller: ‎0
*/

hope that's enough info.. thanks for replying

thanks Keruskerfürst, i try it back again and it worked!