Default fastboot flashing problems

ive look through all methods on how to flash a custom recovery i even ran the batch file that created. and yet still im running into the same problem!! it worked only one time with the custom recovery and once it was flashed i rebooted the devices and then bam!! it somehow flashed back to stock recovery and now everytime i try to reflash a custom recovery my fastboot pops a window saying "fastboot.exe has suddenly stopped working" idk what else to do! i unistall the drivers and i re installed fastboot and adb and still no luck. please anyone help!!! has anyone else run into the same problems after cwm recovery was flashed? all i want is root!! and when i try to fastboot boot (recovery.img) it stays on downloading boot.img and its frustrating bc idk what else to do!!!