Hi Zhukov,

Check the status of touchpad in safe mode.

• Hold the Shift button and mash the F8 key, this will sometimes boot you into the new advanced “recovery mode”.
• Click on the Troubleshoot option
• Select Advanced Options
• Now choose the Windows Startup Settings option, by the looks of things we were never meant to find Safe Mode.
• Finally hit the Restart button.
• When your PC reboots you will be able to boot into Safe Mode from the familiar looking Advanced Boot Options screen.

If the issue persists,I recommend installing the drivers from below link:

http://dell.to/Qj7psu

Also try installing Touch freeze .This Utility disables touchpad automatically while you are typing text.

Install the touch freeze drivers from the below link: 

http://code.google.com/p/touchfreeze/

From the above link, click on Downloads sections, save the file and run the file.

Please reply if you have any further questions.