Emulate User Activity

I want to emulate user activity in Windows machine like left mouse click and further more I would like to perform a pre-defined steps repeatability.

Is there any tool available for that?

Please suggest me an easy and nice way to do it?

I have used AutoIT v3 for a long time and highly recommend it:

http://www.autoitscript.com/autoit3/index.shtml

Recently I've been using Sikuli, and it seems to be a bit faster than AutoIT and is also definitely worth a try:

http://groups.csail.mit.edu/uid/sikuli/

Sikuli is based on taking screenshots to define the areas you want to click and seems to have much less of a learning curve, so if you aren't a programmer or prefer not to code that is your best bet. AutoIT is primarily a scripting language, so you are essentially scripting user actions through code.

If you want it to be nice, you got to do it yourself:

Getting image contents of obstructed window

There's a lot of materials out there that shows how to simulate mouse events using the Windows API.

If you're trying to write your own program to do this:

SendInput (newer) or mouse_event and keybd_event (simpler)

If you're looking for an existing program, then superuser is a better place to ask than stackoverflow.

Check out white on CodePlex

AutoHotkey is the tool you are looking for. It emulates user activity in Windows and more... It is open source and has a wonderful community support:

http://www.autohotkey.com/