My MacBook Pro is acting very slow, it won't open internet apps, and will freeze and lag constantly.?

So I bought a 13 inch Macbook Pro last January and it has been working fine for the most part. That is until this morning when I turned it on and it took more than 2 minutes to show the desktop. First it stayed a minute on the white screen with the Apple logo, then the blue screen stayed there for another minute, and then the items took about 30 seconds to appear once it got to the desktop. My desktop background was also replaced with the default space one. Anyway now it takes forever to open or quit any application(EVEN FINDE!R), and whenever I try to open any of my internet browsers(Safari, Firefox,Chrome) the window won't show up and I have no choice other than to Force Quit. The computer will also flat out freezes if I do simple things like clicking an item or a folder app.



I already ran the Disk Utility application hoping I could Repair the drive but the application told everything seemed Ok with my hard drive and didn't let me do anything else.



I would like to know if anyone knows any other ways of possibly reparing my computer without resorting to going to Apple.My MacBook Pro is acting very slow, it won't open internet apps, and will freeze and lag constantly.?
I'm a windows user though. but try to close some application such as antivirus and unwanted program which start automatically with the OS X