You can try to rename it by MS-DOS (Console in WINXP)
Look for your file in the prompt and then type:
rename <filenamepath.script> <newname.inc>Example: The includes.script file is at C:\mywme\scripts
rename c:\mywme\scripts\include.script c:\mywme\scripts\include.inc
You can do also CD.. to get into the directory, so, you'll have to type less words:
1) cd c:\mywme\scripts\
2) rename include.script include.inc
And you'll have the file renamed
I hope this will work for you