Mount problem

I just checked on my Fedora 11 install which uses Gnome like Ubuntu. My machine (which has a dual boot with Vista), recognizes the windows partitions but does mount them. How do you know that your windows partitions are mounted? It's possible that Ubuntu automatically mounts the windows files.
To Check (I know there is a cli way to do this but....) On the desktop, there should be a Computer Icon, by clicking it it should show you all of your HD partitions. A right click on any of them will bring up a menu, one of the choices on the bottom would be to mount or unmount the drive. If the choice says mount, then, the partition isn't mounted. If it says unmount then it is mounted and you can click on unmount to unmount it. Heh...might've been easier to tell you the cli way.

unmount /dev/sdaX where X is the partition you want to unmount.

As root fdisk -l (that's a small L not a 1) will give you a list of your partitions, mine looks like this:
Device Boot Start End Blocks Id System
/dev/sda1 1 5 40131 de Dell Utility
/dev/sda2 6 1918 15360000 7 HPFS/NTFS
/dev/sda3 * 1918 28026 209718272 7 HPFS/NTFS
/dev/sda4 28027 60801 263265187+ 5 Extended
/dev/sda5 * 28027 28157 1048576 83 Linux
/dev/sda6 28157 33379 41943039+ 83 Linux
/dev/sda7 33379 34423 8388607+ 83 Linux
/dev/sda8 34423 60801 211884031+ 83 Linux

sda2 & 3 are windows partitions, Dell utility doesn't have to be mounted either, but is not a partition used by windows.

Also, mounting partitions doesn't eat up space (or much memory), what did you mean by that?