There are lots of IDE but I want to know why does a programming instructor recommends the use of Turbo c++? On the other hand, I think Dev c++ or Code:Blocks is better and easier to use. Does Turbo c++ has some exceptional compiling speed? or something I am not aware?
I am guessing that your instructor is familiar with Turbo C++ so he is just recommending what he is familiar with. I don't think Turbo C++ is currently distributed or maintained.
If you're a student with a *.edu address, you should be able to get a free copy of Microsoft's Visual Studio 2010 Professional. Its IDE is great with suggestions and pointing out mistakes. Plus it has a lot of other built-in features.
If your school has MSDNAA, then you may be able to get Visual Studio 2010 Premium (the next step up) for free.