In Windows XP/Vista, we cannot create file/folder with the following names: con, aux, nul, prn, lpt(1-n), com(1-n) The reason: those words are reserved as MSDOS device drivers Source: http://support.microsoft.com/kb/74496/en-us But, if you still INSIST to have folder with those names, here is what to do Source: http://kerneltrap.org/node/5772 Run in Command Prompt (Start - Run - cmd) To create folder aux in drive D: mkdir D:\aux\ To remove folder aux in drive D: rmdir D:\aux\ To copy file into folder aux: copy filename.ext D:\aux\ To delete file in folder aux: del D:\aux\filename.ext Note: you cannot copy files to or delete folder manually in Windows Explorer Also, if we already have a file named "test" in a directory, then we cannot create a folder named "test" inside that directory, and vice-versa, if we already have a folder named "test", we cannot create a file named "test" in the same directory. In this case, we cannot trick it even using ...