For some odd reason your system doesn't recognize the choice command. When I run the batch file I see the uninstall question and asks me to press y or n. You see the "You chose to cancel..." because the batch file went straight to the errorlevel 2 I guess, which has that text string trigger. It may be that choice is a command that was introduced in Vista or later version of Windows. Further research is needed on this one. . .
You could get around this right now by opening the batch file in Notepad (either directly or by renaming .bat to .txt) and remove all lines except ones that start with del and rmdir. Doing this will make the batch file vaporise your BW install without any warnings or questions so execute only when you're ready.
It may be painful but you will start with a fresh BW ini file, both BallisticV25.ini and BWCache.ini. If it makes you feel better an update is very unlikely in the near future, if ever, so doing this will future proof you quite well.
