My laptop keyboard sometimes works perfectly , sometimes it just fail when I press on the keys ("-0p[;/") and space key, sometimes they work sometimes not. I have tried to open the laptop, then reset it to the default by taking out the cmos battery. It was running windows 8, but after I formatted and installed win7 operating system. Last time I resetted it, it worked fine for long monthes, then now it is happening again the same issue on the same keys. I have to press several times on the same key. Toshiba p55 core i5 4200 6 gb ram. Windows 7 X64.