OK, this is a picture guide for installing ss6.4 (and thus ss6.3 first, and only if you prefer) on windows vista or windows 7 operating systems.
I used:
Windows 7 Professional 64 bit
MTW II and Kingdoms Disc (non-steam install)
My Gamefront and Rapidshare Files (originally posted by who knows who now probably gracul tho, but reposted/maintained by me so i can vouch for those)
***available here: http://www.twcenter.net/forums/showthread.php?t=417435
Step 1: Turning off UAC
-UAC interferes with games made before UAC was invented/implemented in the windows operating system (a la MTW2). This is due to many reasons, but to summarize the most common, virtual store folder is unreadable by older games, administration restrictions, temp files issues, and read only issues. Feel free to read up on them on your own time, meanwhile, take my word for it, TURN IT OFF for installs, UAC is a good system that works don't get me wrong, but when installing programs, just TURN IT OFF for a bit.
Now how to do that in pretty little pictures:
***Make sure you restart you computer (pic #3) to actually turn off uac
1. Open your control panel and click on system security
2. Click on 'Change User Account Control Settings' (UAC)
3. Move the slider all the way to the off position (all the way down) and click ok, put in the adminstrator password if prompted.
4. Restart your Computer (this actually turns off UAC)
Step 2: Installing Medieval II Total War and Kingdoms to the correct directory
-due to conflicts occasionally with the newer versions of windows (read vista/7/etc etc) older software/games work better when installed outside of program files. (I use C:/Games personally)
***side note: If you have enough space available and prefer it, installing mtw2 twice is not a problem, merely make sure you are pointing the ss6.3 and ss6.4 mod installers at the correct (outside program files) install. I do highly recommend to install any and all mods onto this directory instead of inside program files however.
Now onto installing SS6.4 
First off you need to download the files (available at the link at beginning of the post)
Files needed:
ss6.3.exe
ss6.3-1.bin
ss6.3-2.bin
ss6.3-3.bin
ss6.3-4.bin
ss6.3-5.bin
ss6.4.exe
After downloading all the above files. Please create a folder on your desktop called ssinstall (or something similar) And place all the above files in it: I separated by ss6.3 and ss6.4 but that is not necessary (I did for re-upload purposes)
And inside my ss6.3 folder: (the key is all the ss6.3-?.bin files have to be in same folder as the ss6.3.exe files).
Step 3: Installing the SS6.4 mod
OK, now that you have all the necessary files to install the mod, lets get down to business
:
Step 1: Open up your ssinstall folder on your desktop (and your ss6.3 folder inside if applicable)
Step 2: Right click the ss6.3.exe file and select 'run as adminstrator' from the drop menu
Step 3: follow the on screen prompts and install ss6.3. (make sure to point it at the correct install path: C:\Games\SEGA\Medieval II Total War\mods\SS6.3).
Step 4: Open you Mods/SS6.3 folder and right click ss_setup.exe and run it. (yes this is redundant but better safe than sorry, your only reading this if you had issues anyways)
Step 5: Open and run ss6.3 from your desktop icon and confirm the game is running by opening a campaign and playing thru 1 or so turns. If it works your now running ss6.3 congrats
, hard parts done. If it doesn't please start from step 1 and try again, if still having problems create a thread in the bug reports section.
Step 6: Open your ssinstall folder one more time and right click ss6.4.exe and select 'run as adminstrator' from the drop menu.
Step 7: Follow all the onscreen prompts and instructions and install the mod.
Step 8: Open your ss6.3 folder again and right click ss_setup.exe one more time and select 'run as adminstrator' from the drop down menu.
Step 9: The ss_setup looks like this: (you will see this after step 7 and step 8 both times, feel free to just click the red x to close after step 7 if you wish)
Step 10: Select the start and exit option in the bottom right of the SS_Setup interface and SS6.4 should load up. Exit the game, load up through the desktop icon to test that, and then play a quick campaign for a turn or two to make sure its working.
***If it works your now running ss6.4 congrats
. If it doesn't please start from step 8 and try again, if still having problems create a thread in the bug reports section
Step 11: Re-run ss_setup and choose all the submods you want (if applicable if you didn't do this already in step 8) and start enjoying this fantastic mod.
***Don't forget to run as administrator from the right click menu EVERY time you run SS_Setup.exe so it will overwrite correctly.
-losty- (+rep if the guide helped you)
p.s. And if you have issues/need help please create your own topic in this section and you will be helped a whole lot quicker.