I had the exact same problem and found a cure

I had the same issue and I contacted ACER, my computer's company for help. This is the email I received from them. It solved my problem. Good Luck!Thank you for contacting Acer America. If the mouse cursor moves erratically, it appears that you need to disable the "Tap to Click" feature of the computer.

Frequently when typing, your wrists will brush the touchpad, causing the cursor to jump around or even leave the window. To adjust the sensitivity of the touchpad, go to Control Panel > Mouse > Device settings > Settings, and you should see Sensitivity in the list on the left with + next to it. Click the + next to Sensitivity and adjust the settings to your liking. Also check the Palm Check settings for another way to tweak your touchpad settings. If this still does not solve your problem, it may be that part of your hand is still touching the touchpad. To test this, you can try typing with your touchpad turned off. You can turn it off by holding the FN key, and pressing the F7 key. Use the same key sequence to enable your touchpad again.
Another suggestion is to disable the tap-to-click option for your touchpad. I am including these steps below.
1.) In the system tray (Near the digital clock in the bottom right corner) right click on Touch Pad. This icon will look like a touchpad on a notebook or a red square with a white circular shape inside.
2.) Choose Mouse Properties or Pointing Device Properties.
3.) Click on the tab that says Tapping and proceed to step 4, or click on the tab labeled Device Settings and proceed to step 6.

4.) To disable Tap-to-Click while typing, ensure that the box next to "Tap off when typing" is checked. If this does not correct the issue, or you would prefer to disable the Tap-to-Click feature completely, ensure that there is NOT a check in the box next to "Tapping" (you can also adjust the speed of Tapping or the duration in which Tapping is disabled after you have pressed the last key while typing.)
5.) Click Apply and then OK.

6.) Click on the button labeled Settings.
7.) To adjust Tap-to-Click while typing:
a.) Click the plus (+) sign next to Sensitivity in the left menu.
b.) Click on PalmCheck
c.) To reduce the area required for tapping, move the slider towards Maximum. To increase the area, you can slide towards the Minimum
8.) If this does not correct the issue, or you would prefer to disable the Tap-to-Click feature completely:
a.) Click on Tapping in the left menu.
b.) Ensure that the box next to Enable Tapping is NOT checked.
9.) Click Apply and then OK.
If this does not resolve the issue, we suggest reinstalling the touchpad driver. I am including instructions on how to install the driver from your computer's hard drive, using the eRecovery utility. If this does not correct your problem, you can try downloading the software at www.acerpanam.com, in the Drivers and Downloads section.

1. To start the eRecovery program move your mouse over the Empowering technology widget and click on the eRecovery Manager icon. You may also press ALT and F10 on the keyboard to start the program.
Please note: The first time you access the eRecovery feature, you will be prompted to create a password. Be sure to write this password down somewhere safe. If for any reason you do not have the correct password you will be unable to use any feature of the eRecovery.

The next window will have the options at the bottom of the window.

2. Choose Restore
3. Next, choose Install
4. Click on Windows Vista on the left side of the page
5. Choose driver.
6. In the list choose the item you wish to install
7. On the right click the install link and follow the prompts.
8. The system may restart when installation is complete