I am having difficulty while typing; My course jumps all over the writing pad, sometimes it highlight fully or partially while composing an email  or web site, I have to re- write from the beginning. 
In past I had dll. file missing and I was trying to fix it with download. Could not fix the dll problem but gut the courser as a jumping frog.
Thank you.

Not sure if trolling or having real problem

are you sure you have a mouse plugged in to your computer and not a frog?

It is a problem to me but it may be a funny joke to you.

Here is the joke of the week.

http://sajha.com/sajha/html/index.cfm?threadid=103012

It happened to me once.
#1 REASON: VIRUS (XXX vid kaam hernu paryo kaji)
#2 REASON: Mouse pad (if laptop)/ Mouse itself (if Desktop)

Pepsi: it is Sony Vaio , EB series (  dual core I3  Amd processor, upgraded to 6 gb ram).
Somehow msjster.dll was altered or deleted. I was trying to fix it. Downloaded couple software to fix it. When ever I open Internet  it overtook my aol web page to different one (serach .......). After a week I strarted having  these problem. I am using Microsoft mouse.

magorkhei,
lets end this fuss.

Try to boot in safe mode, and see if your cursor still behaves the same way, if yes, you've a hardware(touchpad) problem but if not you got lucky. Do this :

Start->All Programs->Accessories->System Tools->System Restore-> Select the restore date .. say 1 month back or when your PC was running fine.
(will take 15 minutes or so of waiting)

Best of luck

PS: It looks like browser hijack or some sort of malicious code is running in your system, but just check if you are still able to do the system restore. If your computer is striken with those virus, you need expert help.

Did as suggested. It has slowed down little bit.

NEW:  it is resizing the window ( CTRL plus +  or - ) itself.
Thank you all.

I remember seeing something on this a while back. I had the same issues while I was typing stuff, the cursor would jump to something else. There are fixes that seem to help people but didn't help me. Still worth a try, so google it, you mind find the solution. Good luck.