bootable usb problem

[Punjabian5]

main ne kuch din pehle poweriso ki madad se windows 7 ki bootable usb (8gb) bnai.wo theek ban gai aur main ne us se window b install ki.phr us k baad usay format kr k 1 tool ki madad se usay windows xp k liye bootable bnayi wo b theek bni main ne 1 laptop main wo install ki magr jis laptop main wo install ki us main virus tha jo k d aur e main tha wo meri usb main aa gya.main ne phr us usb ko 1 laptop main lgaya to usb disk security aur eset ne us ka virus clean kr dia.main ne phr utar kr lgai to phr virus show huwa aur phr clean ho gya.phr main ne usay format kr dia aur dobara windows 7 k liye bootable bnanay k liye poweriso ko open kia aur process start kia magr us ne error day dia ye wala

error anay k baad main ne jb my computer open kia to usb k neechay us ki total space ki jaga fat32 likha tha

har dafa error k baad aisa he ho jata hai.format as ntfs b kia.but all in vain
main ne phr format kia magr phr b poweriso main error aa gya.phr main ne usay cmd k zariye format kia.10 mint lgay .lekin phr b poweriso main wohi error ata hai.main ne wintoflash b use kia magr kuch nai huwa.

NOW ANY ONE CAN GIVE ME SUGGESTION ????????