I have a Toshiba satellite laptop. Whenever I try to write an e-mail (regardless of the account I use) the cursor randomly jumps to a previous part of the page.

Is there a bug or a virus causing this?:(

Your thumbs are lightly, imperceptibly brushing the touchpad on your laptop. I do this ALL the time. Took me months to figure out it was me.

You can disable the touch pad, providing you have a mouse (USB connected) to the laptop.

Do you want to do that?