Answer1

There is a perfect tool provide by .net frameworks calles Garbage collector, where by mean of GC we can clean up the object and reclaim the memory.The namespace used is System.GC

Answer2

the run time will maintain a service called as garbage collector.this service will take care of deallocating memory corresponding to objects.it works as a thread with least priority.when application demenads for memory the runtime will take care of setting the high priority for the garbage collector,so that it will be called for execution and memory will be released.the programmer can make a call to garbage colector by using GC class in ststem name space.