how can we make visual studio windows forms attractive
Have a look at
or
Devepress : 100% Native .NET WinForms Components & Tools
The Telerik Rad controls can be "won" once you reach 10,000 rep in SO.
First, think about the purpose the form serves - what does the user need to achieve. Then design as simple, consistent and intuitive a user interface as you can to achieve this. Try to remove as much clutter as possible (is this button really necesary? etc)
Then you need to lay out the elements of the user interface in a clean, consistent, and tidy manner (the rules are exactly the same as for page layout for a graphics design or desktop publishing a magazine page, within the restrictions of the functionality and keeping your app consistent with typical Windows UI).
You can go further (introducing graduated fills, nice artwork, and other graphic design concepts) to make it prettier - but don't go overboard. Too many UIs use a colourful graduated fill in their buttons, which looks nice at first glance, but actually endds up being a visual nightmare once the form has 20 buttons on it. Usually a simple background fill and maybe a nice "titlebar" graphic (think of clean and simple websites) works well.
Generally, "less is more".