Cursor arbitrarly jumps to wherever it may be sitting on the screen. makes typing very difficult

run it in battery to see if fixes cursor problem
also try a different mouse see if that makes the cursor move correctly
this way you see if its the mouse or power supply
might also a touch pad problem anything that controls the cursor

Stop being cheap and learn to spell properly. Go to a proper computer shop and I am very sure they will not charge a lot of money and they will be able to help you. Or your alternative is sell it on olx and buy another on olx!!

Well, technically it is not moving it backwards, it is moving the cursor to wherever the 'pointer' is.
You need to STOP resting your palm(s) on the Touchpad.

When you touch it, it will move the cursor to wherever the 'pointer' is....which is likely where you started typing.

You can also turn-off the touch-pad if you will be doing lots of typing. This is done by pressing [Fn] and [F3].

it is not a problem with your cursor, i think you didnt install the TOUCHPAD program of your Laptop that is why its jumping anywhere, install it to control your cursor on the screen.

your dell laptop are supposed to have a program on touchpad, if you dont have that in your system then the touchpad is jumping

Is the touchpad active?
It is common that users accidently touches the touchpad while writing and this causes the cursor to "jump"...
Another possibility is that the "TAB" key is jammed...

Have you checked the moue and keyboard settings see if there is something in the settings...one computer I would recommend to check the keyboard wiring but with two that would be quite a coincidence. If the mouse is chasing the cursor then its got to be a software issue..also run spyware software on both. Spyware captures keystrokes so could be affecting the keyboard pointer settings.

this is because you must deactivate your touchpad. you can do this by holding the Fn key and pressing the F* key that shows a picture of a touchpad in the same color as the Fn.
or you can go to control panel and turn it off in the mouse settings. but just attaching a mouse will allow the touchpad to stay active and therefore still be sensitive enough for your hand to "tap" th cursor.;
Good luck and pls rank this response! :D

This is a really common problem thats not actually a problem.
Go to trackpad settings and make sure tap to click is off.
Most laptops allow you to tap the track pad to act as a mouse button, try it go to an icon tap the trackpad youll see that the icon highlights as if you are actually left clicking.
When your typing the trackpad senses your arm or wrist occasionaly and thinks your tapping the mouse, thus moving the cursor.
So go into trackpad settings and turn off tap to click.

Since you have a logitech mouse, lets just disable the touchpad. You should be able to disable the touchpad via one of these methods:

1. Look on the top row of keys. You should have one that looks like a little mouse. If you do, hold down the "fn" key in the bottom, and press the key with the mouse on it. That *should* disable the touchpad.
2. Go to the control panel, and find the keyboard and mouse settings. Digging through the menus, you should find a touchpad. You can disable it through there.

Steven