Warp Stabilizer was introduced in CS5.5, Mocha Ae was bundled with CS4. Your options in are to use Mocha Ae or the native tracker in Ae that offers a stabilize workflow. And there's the option of 3rd party plugins but as M said, they might not be compatible with your old version. you can have an updated version of Ae (and all of the other products of Adobe) free fully operarational trial for 7 days, a month based subscription, or join the CC family for a yearly subscription that will be cheaper than a monthly subscription.