Can I get better mouse sampling rates in OpenGL?

My graphics program (that simulates MS paint) requires better sampling rates.

For eg:When I use the pencil-style tool in MS Paint, it draws a free-form line(that’s a set of points). When i replicate the same, with vigorous mouse movements, i only get a set of discrete pixels.
Eventually, I had to settle for drawing lines between the set of pixels thrown by the call-back function to achieve the free-form effect.

Is there any other way to achieve this?
Can i use asynchronous mode, or can I increase the mouse sampling rates, or use a better I/O library along with OpenGL?

No, OpenGL is a graphics API, it doesn’t know about input devices.
Your problem is an OS mouse device driver issue.