To Copy and Move File in the Same Drive
To move file to the same drive just drag it. To make a copy of the file in the same drive control and drag it.
Different drive
Just drag to a folder in a different drive to copy it. press SHIFT key to move it.
+ symbol indicates the copy operation and arrow symbol indicates move operation.
To view and Hide File extensions
To see the exensions in XP, select tools | folder options , in view tab check/uncheck Hide extensions for known file types.
To see extensions in Vista click on Organize|Folder and search Options |View tab to see the same dialog box.