which is ur operating system?

if it is Win xp at the login page press ctrl+alt+del (2 times) amd enter the user name as administrator

or you can also try to contact system manufacturer as v can not perdict your password.

Thats correct, it will take the space of the drive which has Operating system and the operating system will be slow what you can do as a work around is like move the files to other drives or move the files to external HDD and make sure that you are not moving any system files (it wond be saved in the desktop)

before changing this can you answer something?

msn is you home page and bing is you tool bar is that correct?

is you are having msn as your homepage and you want change to yahoo den what you can do is

in firefox go to tools>> options>> in the general tab >> change the home page to yahoo.

if bing is a tool bar you can uninstall from add and remove programs (Win XP) or Programs and features (Win Vista & WIn 7)