I'm trying to restore some files for a friend who messed up a USB stick by pulling it out of the computer too soon. By searching invisible partitions I was able to restore the files. All files are intact, except 1 excel file that seems to be corrupted.

I've googled about ways to repair an Excel file, because the default repair options in Excel 2003-2010 do not work for this file. I've came across a numerous third-party apps, of which the one seemes to be able to do the job: Recovery Toolbox for Excel.

Of-course, this and all other apps I found require a purchase to actually repair the file. It seems a bit silly to pay 30 dollars for a one time thing, and something that is not for myself. So, I would like to keep that as a last-resort option.

Is there anything I can try to fix this? I've attached a screenshot of how the file looks when I open it on my OSX when converted to a HTML file (to view the code), for the option that it could be a character set problem.