The Computer Science test is primarily based on the concepts that you have studied in your undergraduate days but you can not ignore preparing for it. With time your familiarity with the topics is lessened and hence you need proper revision of the concepts. There are a number of means through which you can prepare for the test. You can study on your own, study with your friends, join a coaching center, take online courses or study from softwares. Each of these mediums has its own pros and cons. According to your capabilities and shortcomings you can see which source suits you best.
A GRE computer science test practice book, containing: actual tests; complete instructions and answer sheets; answers; score comparison data; and test-taking strategies.