Good thing is ASUS has a recovery mode. Go to this link on the ASUS site
(the link is for Windows 7, 32-bit. If this is not your configuration, just go to support.asus.com and follow the instructions)
...and download the firmware and the restoration utility which is dated around the beginning of February. You have to install the utility on your computer. Run it and choose the firmware file. (you will have to extract from the ZIP format first).
Cross fingers for a no-brick result...