Dear aspirant, especially for computer questions, there is no issue if you have computer science background. You will be able to attempt most of the questions if your basics are clear. For your preparation you can split it into two parts. For programming, read first 8-9 chapters of 'Let Us C' by Yashwant Kanitkar. For practice use 'Exploring C' by same author and 'C under DOS test' by Vijay Mukhi. Both these books have 400-500 objective type questions on C which will be asked in exam. For other questions, pick the areas you can cover and ask your computer science friends to explain previous year questions.

All the best

Hope this helps