I had the same problem with my Toshiba laptop. I only did a quick search that came up with a fix for HP laptops read up on here.
http://support.hp.com/us-en/document/c02035108
another description here.
http://h30434.www3.hp.com/t5/Other-Note ... d-p/532607
However if you don't happen to have a HP that might not help. I know for my Toshiba I had to go to my little windows tiles menu area (I hate tiles...) and after some extensive digging around found the setting under an options menu that was buried under other menus that allowed me to just toggle having to hold down or not hold down the new little FN key between CTRL and ALT.
I would suggest Googling your brand of PC with the words "Function key toggle" and see what comes up. I doubt you will have to be specific about which model PC you have but you may need to specify what version of windows you have to get the results you need.
I beat my head against the wall for quite a while before I figured this one out myself. To quote Wayne Cambell and Garth Algar "we fear change"
I hope that helps you some, if not maybe a real expert will show up and be able to help. I'm just an ad-hoc trial and error type computer guy.