Windows Defender is a really cool Anti-Spyware from Microsoft that can prevent a suspicious file from making any changes in the computer.
However for proper safety it needs to be updated regularly but for the people who do not have an internet connection or want to save the limited internet bandwidth, here are the steps to update the definitions manually and offline.
1. Following is the location where Windows Defender Definition updates are stored.
C:\Documents and Settings\All Users\Application Data\Microsoft\Windows Defender
2. So just enable the Show Hidden option to view the hidden folders and navigate to above location and copy the entire folder named “Definition Updates”.
3. You need to replace this folder in another computer to update the definitions but do not forget to kill the Windows Defender process before replacing else you may not be able to replace it.
So if you are giving the definition updates to a friend or thinking to format the computer, this will surely save your time and bandwidth.