The garbage collector runs inside a process. So if you want to run the garbage collector for this process you could try the GC.Collect method. You cannot force garbage collection for a given process from the outside.
Also note that forcing garbage collection (using the GC.Collect) method is considered as bad practice and should be avoided.
There is no Microsoft tool and I have never heard of any 3rd party tool capable of doing this. Each process gets its own GC heaps, and therefore its own GC threads, so forcing a GC Collection on another process, AFAIK, is impossible.
