I installed a clean copy of Windows 7 on my laptop and since then I have only installed my anti-virus software, WinRAR 3.80 (evaluation copy) and firefox. After re-booting, the close button on the top right-corner of every program window is grey and I am unable to close with that button. I am currently using the alt-f4 method but am getting a little frustrated with a few programs that won't close automatically when they are supposed to. Advice???