I think you need to also pass the windows share name as well as confirm that you've created /media/Data
sudo mkdir /media/Data
Use something like
smbclient -L //172.29.32.184
to list the shares, then append the share name to your mount
sudo mount -t cifs -o username=raghu //172.29.32.184/sharename /media/Data/
Note- If you receive the error:
wrong fs type, bad option, bad superblock on... make sure you have cifs-utils installed, it may not be installed on your distro by default.
sudo apt-get install cifs-utils
If you need to mount your windows share permanently then there is an excellent HowTo by dmizer UbuntuForums Staff (scroll to the permanent mount section)- I wont reproduce the advice here because its got some excellent debugging hints and tips and other workarounds that you may encounter.