I have samsung galaxy 620 7' inch tablet, it is very good , fast and nice tablet but now I am bored. Can we install windows 7 on this tablet ? It has 1.2 dual core processor with 1 GB ram and that is more than sufficient to run windows 7 on this device .. ?

Is it possible to install windows 7 on this device ?

No the can't be installed on tab because windows 7 can't run on ARM processor. But you can install it on Intel Atom based processor if you can find tablet using atom.