Almost all firmware flashers from the Pioneer and others are now designed to be run in windows. Make sure you do not shut your system off and make sure you have no discs in the drive. As I recall, Pioneer ejects the drawer on occasion so don't panic.
For your info, the Pioneer 107 is fairly well past its prime and you might want to add a Pioneer 111, the best Pioneer drive I have seen and as good as anything made today. At $30 it is a steal.
Here is a good source for your firmware: