If the process described by Toni doesn't fix the situation, give us some more details. I don't have nor use MSWord so cannot comment on its use and anomalous features.
1) screen resolution is 800x600 pixels
What happens if you can set the resolution to 1024x768.
2) the open window program is Microsoft Word document
3) when I press Alt+spacebar+M and move the right or left arrows the screen does not change - remains the same.
I'm assuming from your comment that when the key combination Alt+Spacebar by itself is used....since there is no three-key-combination that I know that works, the context menu in the ULHC where Move is or is not an available option may be off the screen and you don't see it after these two keystrokes. Do you see this menu, and is Move not grayed out?
Caveat: If you're press the M key anyway without seeing whether Move is an available action.... because it is grayed out, then you will not see a four-cross cursor that means movement of the screen is an available action using the keyboard cursor keys or the mouse?
If you can see the context menu after the first two keystrokes....or even if you do, and you see that the Move option is grayed (not an available option), then I would assume your program was started at Maximized from a shortcut, and since the program is being rendered larger than the viewing area, the three boxes usually shown in the URHC of the screen is now off to the right, somewhere unknown.
You're going to have to change the properties of this program shortcut to start it in Normal mode, which hopefully will give you enough screen area to use the Scroll Bar to go left or right to see the above mentioned menu. For example: I start my IE with a shortcut with properties at maximized and I can see the entire display on the screen area. However, if I use the two-key combination described above, I do see the context menu in the ULHC; I also see that Move is not an option and therefore pressing the M key would have no affect since the four-point cursor key would not be rendered since Move is grayed; but since the entire screen is there and I see the three boxes in the URHC, which allows Minimizing, Normal mode and closing of the IE program, I can then click Normal (middle button of the three) which then allows these movement options we're talking about -- try this process/test on something you can see and ascertain whether my gist holds water or not.
4) The up and down scroll arrows are not visible on the screen, and although the left scroll arrow is visible it will not move when I try to scroll - and the right scroll arrow is not visible.
Please. Just a little clarification if we're talking about the screen area and not the mouse cursor (arrows): The up and down scrollable bar on the right of a screen is the elevator and the bottom Scroll Bar allows movement of the screen right and/or left -- when either or both is a viable options however.