How can I change my settings to allow me to remove items off my harddrive?

We recently got a used comp. from a friend it has a Windows XP Professional operating system on it and everytime I try to remove items from the control panel they say silly things such as this is left or write protected and cannot be removed...or it will say it has been removed but it still is not removed.....I need to remove alot off this comp. to make memory available for certain programs I require to load on it......hmmmmm I am lost here I am in the add/remove preograms section right? And when it says click on change/remove I do that but it isnt working...grrrr...What am I doing wrong I certainly am no professional but come on is it supposed to be this difficult to simply make space.......PLEASE HELP???How can I change my settings to allow me to remove items off my harddrive?if you got this pc off of a friend and want more then just a few items removed i would just reformatt the thing if it was mineHow can I change my settings to allow me to remove items off my harddrive?get a 98 floppy disk, enter DOS and format...reinstall XP using the somputer master disks then get your programs. everything will be like new. and nothing will be on.