Unmounting and Mounting directories in Linux to share with windows

Hi,

I have a Debian/Linux system and a windows system

From windows I can share Debian/Linux folder "/home/tgfrmcc" as I drive

Now I need to unmount and mount the same configuration

How should I do that

abcd-pbhi5:~# cat /etc/fstab
# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/sda1       /               ext3    defaults,errors=remount-ro 0       1
/dev/sda5       none            swap    sw              0       0
/dev/hda        /media/cdrom0   udf,iso9660 user,noauto     0       0
/dev/sdb1       /media/usb0     auto    rw,user,noauto  0       0
abcd-pbhi5:~#

abcd-pbhi5:~# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda1             73323196  22286772  47311756  33% /
tmpfs                  1036136         0   1036136   0% /lib/init/rw
udev                     10240        52     10188   1% /dev
tmpfs                  1036136         0   1036136   0% /dev/shm
abcd-pbhi5:~#

Please guide
Many Thanks