Root Help!! disconnect usb while was rooting

[serola]

I was rooting my motorola atrix 4G of a&t. I was following some steps in a forum it saids to turn off my phone then Hold down the power button and downward volume button until you see

 

[james27007]

Did you pull the usb cable before you started to flash or during the flash? Also did you pull the battery, let it sit and try to turn it on again?

At what step exactly did the usb get disconnected from below

1. Extract the ADB-Fastboot package and root image to your C:\ Drive under a new folder titled “root”
2. Put your device into Fastboot mode: – Turn off your device. – Hold down the power button and downward volume button until you see “Fastboot” on your screen – Push the upward volume button
3. Open your command prompt (Start >> run “cmd” >> enter)
4. Type the following commands
5. cd C:/root
6. fastboot flash preinstall root.img
7. fastboot reboot
8. Enable USB debugging (Settings >> Applications >> Debugging)
9. Type the following commands
10. adb shell
11. /preinstall/dosu
12. Type the following commands
13. /bin/mount /system -o remount,rw
14. cp /preinstall/su /system/bin/su
15. chmod 6755 /system/bin/su
16. PATH=/system/bin:$PATH pm install /preinstall/Superuser.apk
17. Congratulations! You are rooted!