Here is some basics on setting up XP9.
First, if you have the latest 6CD version, realise that installation can take an entire day if you install all CD's. Basically its one CD, (CD1) and the rest are all sections of the world in terrain and textures. If you fly mainly Canada, America and Europe, then you will only need 2 of those 5 CD's.
You can install onto another drive. I have mine on an external drive, along with FSX and FS2004. Just place the proper location in the destination bar before hitting the 'Install' button.
If you already have XP9 in C drive and wish to move it, its terribly easy. Transfer the sections of the sim over to a new location Drive into a new X-Plane folder. Then boot it up from that location with your CD1 in the CD drive and it should run fine.
FULL SCREEN MODE / RESOLUTION
After you install it, you will note that there is now 'full screen mode'. XP9 has a 'resolution setting' in its Setting section that you tune for this. Thus you will have 'one' screen size most of the time, unless you wish to change it. The change doesnt happen immediately. Restart the sim after making a change.
For those who have a 24 inch monitor, try 1920 X 1200 resolution setting.
A quick way to find out your monitor setting is to right click your screen and select properties (in Windows) and check your screen resolution there. Then enter that or 'less' for your XP9 screen resolution. Less so you can have your Windows toolbar at the bottom.
VC RESOLUTION AND PANEL DISTANCE PRESET
Next, and this one I think is extremely important.. VC view in XP9 seems to be very 'close' to the panel. They call this 'Lateral Field of View in XP9. In FS, its called Zoom. In XP9, to adjust this to be farther away from the panel (in default zoom), simply go to Settings, go to Lateral Field of View, and plug in something like 70 (for 70 degrees of Lat Field of View), and you should be good to go. Less for closer to the panel effect, more for a zoomed out view.
The change will occur after you reboot the sim. Might as well make all settings changes now, then reboot the sim.
On mine, I also put Texture Resolution (also found in Settings selection center) and set this to 'Extreme' setting. This is your overall textures resolution in the sim, just like in FS.
CHANGING KEYBOARD ASSIGNMENTS
You can also set the regular keyboard selections to FS settings. I found this to be a must for things like VC view (S key) and other such key selections.
To change your Keyboard selections, go to Settings (top toolbar), select Joystick and Equipment, select Keys tab at top, and there you will find all of your keyboard settings entries. Just go through and set which ever you wish to activate what you want in XP9.
There is alot of cross wiring if you wish to change most all of the keys, and XP9 has some cool views and tools (like flight path types shown in 3D for observing your flight, kind of like what students use to see how they are doing in pattern flights), etc, so you will need to write down those keys if you overwrite them with standard FS keys so you can program the XP9 keys back in for them to be useable again. (Taking a key away from an existing command will nullify them until you give them a replacement key, of course).
If you wish to do a LOT of the Keys conversions all at once, you 'might' try using the 'manual' route of programming them. This is similar to going into the FS config file. XP9 has a keyboard config file found here;
XP9 folder/Resources/Preferences and look for the file 'Keys X-Plane.PRF'. Open the PRF file with Notepad. You will see all your keyboard option commands. Just go through that if you like and manually program in the keys into the 'first' points on each line string. If a zone/string/command doesnt have a key, then it will say 'none' in the first section of a string.
Here is a section from the Keys file;
S <none> sim/view/3d_cockpit_toggle
S CTRL sim/view/3d_cockpit_mouse_look
; CTRL sim/view/free_view_toggle
<none> <none> sim/view/show_physics_model
O <none> sim/view/3d_path_toggle
<none> <none> sim/view/mouse_click_regions_toggle
<none> <none> sim/view/instrument_descriptions_toggle
F5 <none> sim/flight_controls/flaps_up
F8 <none> sim/flight_controls/flaps_down
U CTRL sim/flight_controls/landing_gear_up
D CTRL sim/flight_controls/landing_gear_down
Note the top one uses S key to get to VC view, and F5 is the Flaps Up command, etc. This might be faster for you to do a high speed FS key layout conversion. I highly recommend though that you save a copy of this file so that you can change back, fix, copy/paste/repair sections if you mess things up.
I hope that helps..