I have 10 days trying to install skype and I just cant.

Code:
root@bt:~# dpkg -i skype-ubuntu-precise_4.1.0.20-1_i386.deb 
dpkg: error processing skype-ubuntu-precise_4.1.0.20-1_i386.deb (--install):
 package architecture (i386) does not match system (amd64)
Errors were encountered while processing:
 skype-ubuntu-precise_4.1.0.20-1_i386.deb
I have found people with the same problem and a lot of different solutions and it just doesn't work to me.
I have tried more of 15 different solutions and now i realize Skype is already installed (it is in Internet > Skype). But when I click it to open it do nothing,
some one know why?

Additional Information:
Backtrack 5r3
Architecture 64
Installed in the hard drive