why does my browser think my cookies aren't enabled?

My computer started off with some serious problems, locking up, automatic updates would not turn on, etc. My friend managed to fix most of them except the fact that when i try to log into myspace or other sites like that it tells me i must have cookies enabled to log in....so i go to internet options and it shows cookies are enabled. It looks like my browser is mistaken...or my computer is mistaken or whatever. I'm not a whiz with the computer so I'm looking for someone who may know what the problem is.