After installing magento, I go to admin pane system -> magento conncet -> magento connect manager, i paste the extension key to install, then clicked on proceed to install. In magento connect manager console at bottom it show
checking dependencies of packages starting to download Varnish_Cache-4.0.5.tgz ... ...done: 34,730 bytes
It does not further move to installation process.
Is the problem of my installation? or permission problem ? or some think else ? I am unable to install any extension due to this big problem. I am new in magento 
Thanks in Advance.