Sorry for bringing this thread up, but it was only thing so far that has worked ... some what.
Have the same problem as what the original poster mentioned: no visual cursor on screen, and trackpad is non-responsive even though when I press fn+f1 I can disable or enable it according to the onscreen pop up messages.
I have tried the response from YuriF:
1. Turn the computer off completely.
2. Disconnect all the connected devices including the AC adapter. Flip it over.
3. Locate the battery off button. Grab a paper clip or a pin, then press and hold the button down under the hole for 5-7 secs.
Release it afterwards. (your files are safe, don't worry)
4. Plug the AC adapter back. Put it back to normal position.
5. Press Assist to check VAIO Care Rescue. Then hit F2 (Start BIOS Set-up)
6. Go to EXIT tab > down to Get Default Values. Hit Enter and say YES.
7. Highlight Save Changes under EXIT tab still, then ENTER and say YES.
8. Go up to Exit Set-up, hit Enter and say YES.
9. Now, back to VAIO Care Rescue, choose Exit to Windows 8. Observe what will happen.
Starting step 1 above, my cursor is not present ... but after after step 9, it works ... but only in the VAIO Care Rescue program. Once I restart and go to the login screen the cursor and touchpad are not present again.
Any suggestions?