Format the thumb drive
from a elevatedprompt execute
diskpart
list disk
select disk 1 (assuming disk 1 was your thumb drive in the above list disk command)
clean
create partition primary
select partition 1
active
format fs=fat32 quick
assign
exit
Unpack the ISO,copy the fileson to the newly prepped disk…
xcopy SourceDrive:\*.* /s /e /f DestDrive:\
(Works with WIndows server 2008,R2,Vista,W7 m.m.)