Why does my pointer sporadically move around and click on it's own sometimes?

Buy a new one and see if that cures the problem.

Can you provide a complete model number? If this is a top loader check the lid switch. You should hear a click just after opening and a click just before it's closed.

Double click on pad surface. Buttons could be faulty. Check mousepad settings. Install drivers

Step 1

1. Open Mouse by clicking the Start button, clicking Control Panel, clicking Hardware, and then clicking Mouse.
2. Click the Pointer Options tab, and then do any of the following:

• To change the speed at which the mouse pointer moves, move the Select a pointer speed slider towards Slow or Fast.
• To make the pointer work more accurately when you're moving the mouse slowly, select the Enhance pointer precision check box.
• To speed the process of selecting a choice when a dialog box appears, select the automatically move pointer to the default button in a dialog box check box.
• To make the pointer easier to find when you move it, select the Display pointer trails check box, and then move the slider towards Short or Long to decrease or increase the length of the pointer trail.
• To ensure that the pointer doesn't block your view of the text you're typing, select the Hide pointer while typing check box.
• To find a misplaced pointer by pressing the CTRL key, select the Show location of pointer when I press the CTRL key check box.

Change mouse settings
http://windows.microsoft.com/en-US/windows7/Change-mouse-settings

Step 2

If you are using touchpad, try reducing the Touchpad sensitivity and check

1. Click on the "Start" icon in the lower left corner of the screen. Select "Control Panel." Next select "Mouse" under "Hardware and Sound." You can also left-click the touchpad while the cursor is anywhere on the desktop. From that screen, choose "Mouse Pointers."
2. Select the "Buttons" tab at the top of the dialog box that opens. This shows the type of touchpad device installed on your laptop.
3. Set the touchpad for right or left-handed use from this dialog box. You can adjust the double click speed of your computer as well. When you finish making any changes, click "Apply."
4. Pick the "Device Settings" tab from the dialog box now. You can see the touchpad for your Vista machine highlighted on this screen. Select "Settings."
5. Read the information provided in the next dialog box. It gives you options for tapping your touchpad, using the buttons, scrolling, pointer motion and sensitivity.
6. Make any changes you want from the various topics. When you make a change, click "Apply." Click "OK" when you finish making all your changes.
7. Do some work on your computer for a while, If the touchpad is still too sensitive, return to the "Mouse" menu and continue to adjust the settings until you get them just the way you want them.

Step 3

If the issue persists try to perform a clean boot and check whether the issue is still persists.

Follow the steps mentioned in the article given below.

How to configure Windows Vista to start in a "clean boot":

http://support.microsoft.com/kb/929135

Note:Once the troubleshooting is over, reset the computer to start as usual.

Also I would suggest you to keep in touch with mouse manufacturer

Step 1

1. Open Mouse by clicking the Start button, clicking Control Panel, clicking Hardware, and then clicking Mouse.
2. Click the Pointer Options tab, and then do any of the following:

• To change the speed at which the mouse pointer moves, move the Select a pointer speed slider towards Slow or Fast.
• To make the pointer work more accurately when you're moving the mouse slowly, select the Enhance pointer precision check box.
• To speed the process of selecting a choice when a dialog box appears, select the automatically move pointer to the default button in a dialog box check box.
• To make the pointer easier to find when you move it, select the Display pointer trails check box, and then move the slider towards Short or Long to decrease or increase the length of the pointer trail.
• To ensure that the pointer doesn't block your view of the text you're typing, select the Hide pointer while typing check box.
• To find a misplaced pointer by pressing the CTRL key, select the Show location of pointer when I press the CTRL key check box.

Change mouse settings
http://windows.microsoft.com/en-US/windows7/Change-mouse-settings

Step 2

If you are using touchpad, try reducing the Touchpad sensitivity and check

1. Click on the "Start" icon in the lower left corner of the screen. Select "Control Panel." Next select "Mouse" under "Hardware and Sound." You can also left-click the touchpad while the cursor is anywhere on the desktop. From that screen, choose "Mouse Pointers."
2. Select the "Buttons" tab at the top of the dialog box that opens. This shows the type of touchpad device installed on your laptop.
3. Set the touchpad for right or left-handed use from this dialog box. You can adjust the double click speed of your computer as well. When you finish making any changes, click "Apply."
4. Pick the "Device Settings" tab from the dialog box now. You can see the touchpad for your Vista machine highlighted on this screen. Select "Settings."
5. Read the information provided in the next dialog box. It gives you options for tapping your touchpad, using the buttons, scrolling, pointer motion and sensitivity.
6. Make any changes you want from the various topics. When you make a change, click "Apply." Click "OK" when you finish making all your changes.
7. Do some work on your computer for a while, If the touchpad is still too sensitive, return to the "Mouse" menu and continue to adjust the settings until you get them just the way you want them.

Step 3

If the issue persists try to perform a clean boot and check whether the issue is still persists.

Follow the steps mentioned in the article given below.

How to configure Windows Vista to start in a "clean boot":

http://support.microsoft.com/kb/929135

Note:Once the troubleshooting is over, reset the computer to start as usual.

Also I would suggest you to keep in touch with mouse manufacturer

I would power off the computer and continously hit the space key for a few minutes. It might have a liquid spill such as a soda pop under it and causing it to stick. If that doesn't solve the problem you might need a new keyboard or go inside the laptop and remove the keyboard cable and plug it back in to reseat it. Sometimes that helps. Here's a fail safe alternative. Bring up google's website www.google.com and in the search box type "download.cnet.com" (without the quotes) and click the link to go to their site. When the site comes up look immediately to the left and you will see a gray area that says Find Software. Type in "free virtual keyboard" (without the quotes) and click the mirror to search. It will bring back a page and the Free Virtual Keyboard is listed first. Look to the right of it and click the Download Now button. Download and install it. Once it is install you can look in Start/Programs and right click on it and select Pin to Start Menu then right click again and select Desktop (Create Shortcut). It's a neat keyboard to have just in case your real keyboard goes bonkers. You simply click on the letter with your mouse pointer that you want. It has all the functionality of a physical keyboard. You can open a web page, place your mouse in the address line then bring up the virtual keyboard by clicking on it from your desktop or start menu and it will sit on top of whatever you were trying to do. You can move it to see the typing area as you click on a letter. It works the same way if you opened a word document. In your case anytime you need the space bar, just click on it.

Replace the mouse with a new optical mouse.

Press the Index Sheet and scan buttons at the same time. Use buttons to select cartridge replacement. Lift lid and change carts.

It may be in "accessibility" mode.

Tap the touchpad five times. A message will appear. Change it to normal mode, disable accessibility option.

try the on/off button with the lid open. it should move the cartridges.