Don't. I've lost count of how many people visit various forums to cry about how flashing with a windows app went wrong and killed their MB.
same tool ive used many times without failure.. assuming that we're talking about flashing the bios to a later revision, and not adding a SLIC table??
I used the same tool to flash my bios twice with slic 2.1. Both where flashed without problems. (and i flashed in Windows 7)