I was not able to reproduce the problem on my WinXP. According to Google, this error message usually means the software contains debug code, which should not happen if you are using the GA releases. I'd suggest you try a different package - if you installed from the MSI installer package, then try the non-install ZIP package, and vice versa. If it still doesn't work, I guess you'll have to use the command line client, which is actually quite easy to use as you'll see in class next week.

Thanks to both respondents.  I was able to get MySQL Workbench to work by first installing the MySQL DBMS as instructed using the .msi download then installing MySQL Workbench using a different .msi download for the workbench.