open the file up in a text editor and start deleting

 

you have to have it set to show the extensions... then you just rename it like normal. just type .whaterver you want.

 

ahh...mine hides the extensions...h:

 

this used to happen a lot in my computer science class last year...except, it was found that students who saved their projects on certain school computers couldn't read the file on the one in the lab. Later, they found the A: drives on these certain computers were damaging the disk upon writing to it.

 

Tools/folder options/view, my young Jedi.