What is Error 17?

Error 17 occurs when the checksums don't match. This essentially means that the file is corrupt and you need to redownload it. This can happen when you download in the first place, if it gets corrupted in transfer, or while unzipping etc... Windows does many things in the background and sometimes this just happens. Simply redownload a fresh copy of scrapebox from the download link:
http://www.scrapebox.com/payment-received

If the problem persists then you should try using a different unzip program, you can google for this, there are many free ones.