Trouble when typing on the keyboard on my sony vaio

No, this is usually a faulty nipple. the easiest way to correct this is to remove the keyboard, remove the keyboard connector which is a thin ribbon cable, then slip a piece of paper in to block the thin connections for the nipple (not blocking the keyboard pins, you'll see the difference).

Did you upgrade to win10? Then you might need to download the older win7 drivers and load them, remove the win10 trackpad driver first then reinstall the win7 ones..
You can find them here https://esupport.sony.com/US/p/swu-download.pl?mdl=VGNFZ240E&upd_id=3049&os_group_id=10 Sony eSupport VGN FZ240E Drivers Software

Hello
If the new keyboard is behaving same, then try to plug in an external keyboard to see if that works okay. You can use any USB keyboard. If this keyboard works, you have a hardware problem and need repair from Sony Support.
Hope this helps, Good Luck

That key on the keyboard is stuck. If you can't unstuck it you will have to replace the entire keyboard.

The reason this is happening is that as you are typing; you're resting some weight on the thin plastic above the touchpad...which then makes contact and registers a 'click'; thus moving your cursor around.  Or you're brushing your thumb against it when hitting the space key.

Some laptops are more susceptible to this than others.  Some more modern laptops come with a button to turn the touchpad off to solve this very problem.

The only thing you can do about this is to disable the touchpad through the touchpad driver (down by the clock, usually) and use a mouse instead.  Depending on how you use your laptop, this will be more or less inconvenient- if your laptop never leaves the desk; disable the touchpad and use a mouse...no problem.  If you go mobile a lot, you'll have to enable and disable the touchpad all the time.

The other thing you can do is adapt your typing style so you don't put any weight on anything but the key you're pressing.  This is quite difficult and uncomfortable, and is not recommended for long sessions.

Im having a similar problem , have you got it fixed yet? I really need some help the scrolling feature on my Vaio VGN - FZ31S does not work at all and I have tried everything.

i think its a mouse pad problem, disable the mouse pad , and use external mouse and try. i think your problem can be solved this way.

it is not a problem with your cursor, i think you didnt install the TOUCHPAD program of your Laptop that is why its jumping anywhere, install it to control your cursor on the screen.

maybe its keyboard problem ,some keys on ur keyboard.open a new text document and test all the keys of keyborad if any type more than 1 times when u push u have to clean under that key .

You can try using and typing :" driver VAIO PCG-GR300P " ( ex: using : google search ) there is many alternative web to dowlnload driver for you