This information is for the programmer. Not being a posessor of any Microsoft source code, it's not going to be much help.

You really need to get the skipcredits.txt setup properly. Follow these instructions exactly:

1) right click your desktop
2) select "new"
3) select "text document"
4) rename the file now on your desktop as follows:

If the file appears as "New Text Document":

Rename it as "skipcredits"

If the file appears as "New Text Document.txt":

Rename it as "skipcredits.txt".

5) you should now have a file on your desktop called either: "skipcredits.txt" or "skipcredits". The icon for this file should be like a small page of a notepad containing a series of small horizontal lines. When you double click on this icon, a notepad window should open. The document should be blank. If the notepad window opened close it. If it didn't open and/or the icon doesn't resemble the description above, then you've done something wrong.

6) assuming all went well, you now need to move this file to the %systemroot%\Total War\medieval - total war\ folder. This may be e.g. C:\Total War\Medieval - Total War\ or it could be any directory that you installed the game to. This directory will always contain the MTW program itself. This file is called Medieval_TW.exe (or Medieval_TW). You should place skipcredits.txt (or skipcredits) in the same directory as this file. If it is not placed in the same directory it will be ineffectual.