Problem is in TRACK STICK, not touchpad per se.
In Dell Latitude E6400, the following fix was found. Problem was very bad, cursor pulled off to side even in the system bios. We still have no fix for that part. Once windows starts, use keyboard navigations. There is in the Control Panel a Mouse item, choose that, wander through settings until you get to the thing where you can disable the track STICK.
In this system, we sometimes could get a USB mouse to work, so we could use the machine, but that required a BIOS setting that disabled the touchpad while USB mouse was installed. You may try that in order to start windows and then change your mouse settings. However, once you disable that stupid track stick, then you can turn on touchpad.
Also, in Win 7 mouse settings, I found an option to use software to turn off touchpad while mouse is installed. That helps quite a bit, inserting the use mouse brings up a warning.
I got no satisfaction from dell on this. THey did replace the touchpad in the end of the warranty period, but trouble with drift began after that, and their answer was "too late for you". Too bad. Will buy Mac or Sony or other hardware next time.