Which is better for a student studying Architecture , a Windows operating system or Apple Macintosh ?

Check with the Architecture department at your university (or the one you plan to attend). I did tech support for an architecture school at a university several years ago, and our labs were 50% Mac and 50% Windows. The Windows machines were used for software like AutoCAD and 3D StudioMax, while the Macs were used for smaller apps. Other architecture schools may be closer to 100% Mac or PC, so see which environment is being used by the place you wish to attend.