Sounds like you're making contact with the touchpad while you type. Try turning off tapping on the touchpad 1. Open Control Panel 2. Click to open Mouse icon 3. Click Device Settings tab 4. Click Settings button 5. Find Tapping setting and uncheck it to turn it off
I have a Vaio VGN-FW550F that I recently upgraded to Windows 8 Pro and I'm having a similar problem... it is really a maddening problem. So far I've tried the following remedies, none of which had any effect:
Completely disabled the laptop's touchpad (using a mouse instead)
Installed Touchpad Settings Update 1.0 from the support page for this laptop; it specifically mentions this issue.
Installed Settings Utility Series Update 184.108.40.20600 from the support page for this laptop. On another thread on the Sony message board, it was mentioned as a remedy for this issue.
I'm looking for any suggestions... or hope Sony is working on an update to fix this.
Welcome to the New community, hope you like it better than the previous forum boards.
As for the cursor moving around, The Touchpad driver is not the issue, the problem is the Touchpad Utility, or the lack thereof.
If you go to mouse properties and see the following
it is very likely you have had the touchpad utility replaced with the above, default USB mouse properties that is missing tapping, as well as scrolling functions. This is causing your erratic behavior.
As for your VGN-FW550 the issue is you also are missing control drivers. Unfortunately the VGN-FW550F is not supported for Windows 8 at this time.