My OPT will be expirng on Jan 30th 2013, so I am planning to take a new I-20 for spring 2013. I am planning to work during the spring-2013, so my question can I take CPT in spring-2013, since I have already completed my OPT? Please advise.
If you meant going for a CPT after you have completed your OPT, you cannot take a CPT once you have graduated for the same degree. CPT are generally in between your studies, not after you graduate.
If you have graduated with a STEM (Science/ Engineering/Math) degree, you can apply for a 17 month OPT extension.
Under assumption that you mean taking a new I-20 as to joining a new course in Spring 2013:
Most of the universities dont allow CPT from the first day, but if they do, they may be universities that violate visa rules. You may get into legal trouble as it happened with two universities recently. Most universities allow CPT only after 9 months of joining the course.