Default REALLY need help

ok so i can get into fastboot and download mode. i dont know what i idid but i think i really ****ed up my phone. i really need help to either go to stock or a modded ROM either is fine. my variant is the wind variat (which i believe is the T-mobile equivalent)

please help me guys ige tried a few of the methods here but i am on windows 8. if i have to ill go to my brothers really slow win 7 computer but i really need help