Ashish 
I just flashed n re portioned 2 gb sd card and flashed the given superboot-6410 file to sd card. as i insert it in to my tiny6410 n change s2 to nand and switch it on. led1 will be blinking.. it tried all switches. Later on, i ran DNW as directed.. by http://www.friendlyarm.net/dl.php?file=download.pdf. from then on i couldn't do anything.. My tiny6410 is pre installed with Qtopia, but i need to change it to windows ce. M trying a lot to change OS but m not getting any source to change it.. pease any one uide me with complete details how to change the os.. and please do attach required files for changing OS