Laptop touchpads are the cause of "jumping cursor" syndrome. You can accidentally brush the touchpad with your palm while typing, causing cursor to jump around the screen. Sometimes you don't even need to brush the touchpad and the cursor still jumps because of driver/hardware issues, and believe me, it is very annoying. There is a software solution for that - a free program called TouchFreeze
, but it doesn't always work. So the ultimate solution would be to disable the touchpad and use the external mouse.
This looks like a trivial issue but in fact it is not. Sony Vaio, in particular, will not let you disable the touchpad in BIOS or in Device Manager. Most instructions on the web will tell you to "Open Vaio Control Center, expand Mouse and Pointing Device, find checkbox that says Enable and uncheck it..." Well, guess what? It works only when laptop is fresh from the store with all factory default software installed. As soon as you made a clean install of Windows 7, all Vaio software is gone or stops working properly.
This instruction will tell you how to restore Sony Vaio software and bring this "Enable Pointing Device" checkbox back from abyss.