Hallo Salil, I am not familiar with McAffee but i have seen others post with the same problem.
If i recall correctly the fix was to uninstall McAffee and then run uninstall tool (in safe mode)
You can download the McAffee Uninstall from the link provided in this post list of anitvirus removal tools
put together by one of our members.
You can enter Safe mode by repeatedly tapping F8 during startup, once you have run the tool restart your computer.
You can now install then update your latest version of McAffee & hopefully your problems should be resolved if not post back & see what solutions other members may have.
Just a note if McAffee has its own Firewall then make sure Windows Firewall is turned off