@Ishani
as u r trying to change windows system protected files.... they will not allow you to change them while windows is running ....
first of all save the file with the same name as u opened but to some different location ...
then u can use " Replacer " software to do ur job....
it will ask u 4 the file which has to be replaced ... just drag it and leave it in tne replacer window ....
then it will ask u 4 the file with which it has to replace .. again drag the file and leave it in the replacer window ....
it will replace the file at next reboot. .....
i am giving u the link below to download replacer ....
*www3.telus.net/_/replacer/Replacer.zip
and u can refer to the following thread 4 more information ....
*www.thinkdigit.com/forum/showthread.php?t=30897
i hope this will solve ur problem ....
