Lenovo z580 key appears stuck!

Registration date
Wednesday November 14, 2012
Last seen
November 14, 2012

Some things have been very helpful on this site and I am very happy that I found You guys!
But I still need help! I have an Lenovo z580 Ideapad laptop,it's 2 months old and I had no problems with it till a few days ago! I'm not sure what could cause the problem but I know for sure that even formating the system disk and insalling windows 7 and windows 8 for numerous times didn't fix it! The problem is: my komma (,) key appear stuck upon windows logon! Nothing ever happens when I boot or even when I'm supposed to press any key to boot from dvd when doing a fresh install on my laptop! So nothing happens till a few seconds after logging in my account, then I hear the windows sound when you have an error an I se on the start menu in the search area this ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
I'm desperate,what could it be! Please help me! Thank You all in advance!