loader.bin should not exist in current Pi firmware. It was removed in October 2012.
I am not sure what three flashes actually means these days, but you do not want to try to repair the firmware in place anyway. Evidently something went wrong installing the image onto the SD card, so you need to try again rather than attempt to fix it.
Make sure you have no programs or windows open during the install, and that you "safely remove" the card before ejecting it. If you have difficulty installing a Raspbian IMG file you might try the NOOBS installation method instead (or vice versa). The two methods use different software, so are not likely to have the same failure modes.