hey dude u have must make your retrun from the software which was purchased from private vendor, because software which is avbl from www.tin-nsdl.com
now the solution is when u validate the return the FVU(file validation utility),is generated .
now try to find out that file, then open the revise return option,then click on the open file option, after this it will ask u the original FVU file,then give tha path of that file
after this your previous original form will opened then make the correction,& file the revised return
but remeber one thing while filing revised return y have to submit the photocopy of the acknowledgement of original return