Question

1- is the ROM memory and the H.D.D (Hard disk) the same thing?
2- the TREE command of DOS had never worked, shoud I instal The DOS or the MS-DOS of windows xp will do it?
thank you for your help.

Answer

Regarding your first question. ROM memory and your hard disk drive are not the same thing. ROM is memory that can only be read from but not written to. Where hard disk memory can be read and written to. We highly suggest you review the below dictionary pages.

ROM definition:
http://www.computerhope.com/jargon/r/rom.htm

Hard disk definition:
http://www.computerhope.com/jargon/h/harddriv.htm

Memory (Non-volatile / Volatile):
http://www.computerhope.com/jargon/m/memory.htm

Regarding your second question. The tree command works from the MS-DOS prompt so make sure you're running MS-DOS from the command shell by clicking start / run / typing command and pressing enter. At the MS-DOS prompt simply typing 'tree' should display a tree.

If this command does not work, you cannot reinstall just MS-DOS as it is a part of Microsoft Windows XP and not a separpate program. Therefore to correct this issue you may have to completely reinstall Windows XP.

Additional information about the tree command can also be found on the below link.
http://www.computerhope.com/treehlp.htm